Upon a VERY brief look as i should really be working :icon_blushing: I would agree with everything sthomas has said (especially about the lack of styling of the text) and also add that if i was looking to buy a car i would want the option of viewing the pictures at the highest possible size.
There are a few issues of the text going over the allocated box, and i think you need to do something much more inviting with the "latest cars added" part of the home page.
I would also want the option of searching a lot more than just manufacturer and model. Price, location, engine size, colour, doors, etc. are all going to play a part when searching for a new car. You're competing with the likes of autotrader here which is obviously going to be peoples first place to go when looking- so you need to up the bar.