There is some used buying advice (US) in these posts:
http://autos.groups.yahoo.com/group/.../message/55692
http://cartalk.com/board/showflat.ph...&Number=344047
http://autos.groups.yahoo.com/group/.../message/23414
If I can quote myself from the old cartalk board (before they take it down!):
from 6/21/2006
The 2001-2003 "Classic" Prius are essentially the same.
The main changes for the US 2001->2002 were additional exterior color choices (Brilliant Blue Pearl (dark blue) and Blue Moon Pearl (light blue/purple or lavender color)), side air bags option, and the navigation system option, and cruise control option. (There were a few VIP US 2001s (to Toyota execs, Jane Fonda, other celebrities, etc.) that had some of these 2002 options... also, Hawaii 2001s may have had these options as well.)
The only real change from US 2002->2003 were some exterior color options (remove Blue Moon Pearl, add Black and Golden Pearl (off-white/champagne color)).
Note that you can add cruise control to a Prius that is not already equipped with it. (I've personally added the Toyota cruise control retrofit kit to my US 2001 Prius.) Same goes for a CD player or 6CD changer, or alloy wheel locks, or floor mats...
You cannot add side air bags later. Although there is already the display screen and dashboard buttons on all Classic Prius, it is prohibitively expensive to add the navigation system (too many missing parts and much labor) later if not already equipped. (So, be sure to ask what the navigation DVD version is if someone says that navigation is installed, as some sellers may assume that because the buttons and the screen is there that the navigation option is installed when it really isn't...)
At least for the US, all warranties are transferrable to the new owner.
Basic: 3 years/36,000 miles.
Powertrain: 5 years/60,000 miles.
Hybrid system (includes hybrid battery): 8 years/100,000 miles.
I don't have handy the rust-through or the federal/CA emissions systems warranty periods.
(The Classic Prius was not AT-PZEV rated, only SULEV rated, so no extra CA-emissions warranty on the hybrid battery pack.)
In the US, the 2001-2003 Prius also came with the first 5 regularly scheduled services (6 month/7500 mile intervals) complementary (free) from Toyota. That's out to the 2.5 year/37500 mile service. The free services also transfer to new owners, but you may have to politely remind your service department to not charge you (show them your Prius Passport to Performance (scheduled maintenance guide) where it says it's free...). If you don't get one with your car, you can download it from
http://smg.toyotapartsandservice.com/
Also in the US, the 2001-2005 Prius came with a free subscription to the Toyota Roadside Assistance for the first 3 years/36,000 miles, and this also transfers over to new owners. Besides your usual roadside assistance benefits, this plan includes a Tire and Wheel Road Hazard Warranty, which can be helpful if you need to have a flat repaired or such.
The later build date you can get in 2003, the better, to make sure that all the small "issues" may have been worked out. The CD player/changer wiring harness parts changed in 2003, to stop a common install problem, for example. That's not to say that even an early 2001 wouldn't be a great car for you.
If you get an early build 2001 Prius (built early summer 2000), check that it wasn't part of the power steering rack recall.
Several 2001-2002 Prius have had some steering rack "shudders" - most
notable when starting from cold and in reverse - where the power steering causes the steering wheel to oscillate on its own back and forth a bit... Toyota issued a 5 year/unlimited mileage extended warranty on the power steering rack for this problem. So, see if the previous owner has had any such issues, and if the steering column was replaced for this. (I'll note that I've never seen this on my 2001, so it's not every car that's affected...)
Nearly all 2001-2003 Prius (some later 2003s excluded) were subject to the (Special Service Campaign) SSC 40G, which is a preventative hybrid battery checkup and sealant to prevent some minor electrolyte leakage/corrosion. So, make sure that this (free) procedure is done before you buy the car.
It's not uncommon for some 2001s and maybe 2002s to have had an ECM (computer) replaced (upgrade to new firmware to not throw false error codes), so don't worry about that if it's been done or not done.
OEM tires for the 2001-2003 Prius in the US are:
Bridgestone Potenza RE92 XL (Extra Load)
P175/65 R14
84S
Treadwear 160
Temperature A
Traction A
new tread depth is 10/32"
Do check that the installed tires have the correct load rating. It's really difficult to find a tire of the same size with the 84 or higher load rating. (Also note that there is a Bridgestone Potenza RE92 tire (as sold for the Toyota Echo I think) that does not have the XL rating, so be careful that you get the right one!)
Most owners seem to get in the 20,000-30,000 mile range with these OEM Bridgestone Potenza RE92XL tires, by having a properly-aligned car and keeping the tire pressure at a minimum of the factory-recommended pressures of 35psi front, 33psi rear, check the pressures regularly, and rotate their tires at 5,000-7,500mile intervals. But, uneven tire wear (wear on the outside edges, most notably on the front tires) is unfortunately common...
....
(When sold new, the MSRP of an optionless/accessoryless Classic Prius was $19995 + about $500 for DPH. (IIRC Navigation was +$1900 and side air bags was +$250) )
from 7/23/2006
I didn't note earlier about how you can tell the build date on the Prius. On the door jamb plate (or maybe under hood/bonnet), look at the top right corner.
Here's a photo of a plate from a US 2002 Prius (NHW11L), build date Sept. 2001:
http://www.kluge.net/~felicity/pics/...o/PC250403.jpg
Also, I'll note that there is a ... recall on some late 2001s/early 2002s, SSC 60G, to replace the crankshaft position sensor.
http://pressroom.toyota.com/presstxt...el/SSC-60G.pdf
Make sure that all applicable special service campaigns have been performed! Many of them are listed in the files section of the toyota-prius-sat1 yahoogroup (free membership):
http://autos.groups.yahoo.com/group/toyota-prius-sat1/
On such a mileage Prius, I would be sure to check on the brake service history or at least have them inspected. Low mileage Prius tend to accumulate brake rust from non-usage, which then causes premature/uneven wear/scoring of the brake pads. Normal or high mileage Prius tend to have long intervals before needing brake pad replacement.
Assuming that a Classic Prius hasn't been declared/titled a salvage vehicle, it should still have almost a year warranty on the hybrid battery (assuming it hasn't passed the 100,000 mile mark). Used (salvage) hybrid battery replacements are still under $1000.
It has also been suggested on several owner's group that the transmission fluid should be checked/analyzed, and preferrably replaced. Again, check the service history. Sadly, transaxle replacements are about as common as hybrid battery replacements, but thankfully reports of either are very uncommon (rare)!
There are many Classic NHW11 and even some of the newer NHW20 Prius that have well over 100,000 miles and no battery problems, and just because a warranty runs out doesn't mean that that component needs replacing. The hybrid battery should last the lifetime of the car. The rumors you've heard is just scaremongering, as the Prius well monitors the battery and its charging parameters make sure that it lives a long life.
My only concern for you is that a used 2001-2003 Classic Prius may not be as big as you're used to, being a compact sedan (and your 2007 Accord being a midsize sedan), the same size as a Honda Civic. If size is an issue, look into a used 2004-current model year Prius (now a midsized hatchback), or a used Honda Accord Hybrid, Toyota Camry Hybrid, or Nissan Altima Hybrid or even a Saturn Aura Hybrid/Chevy Malibu Hybrid, which are all in the same midsize size class.
If you have questions about whether a specific used Prius is a good buy or not, I might suggest asking some owners:
http://autos.groups.yahoo.com/group/toyota-prius/
http://www.priusonline.com/
http://www.priuschat.com/