http://www.toyota.com/yaris/features.html
It would seem that the Toyota Yaris has standard 4-way adjustable driver's seat. (I'm guessing that that is front/back on track, and reclining back seat.)
The driver's seat height adjustment is standard on the Toyota Yaris sedan, but is not available on the Toyota Yaris liftback.
As a shortish woman, I understand your problem. You really need to find a car that fits you and makes you feel comfortable, as you're going to be sitting in it driving for many hours over the time that you own it... I've had some good luck with some nice pillows, and there's one from Brookstone that I hear many good reviews on, if you're set on the Yaris and the seating is not tall enough for you.
Does the 2009 Toyota Yaris have height adjustment and reclining for the driver's seat?
Linear Mode
