I think you need to decide which market you're trying to attract.
One one hand, the main panel of images looks like it could be from a high-end car showroom while the rest of the site looks very cheap and bargin basement.
I realise that it's still a work in progress but the fundamentals of a well-styled and easy to navigate website still need to be in place.
The other main issue is the styling of the text (or lack of). At the moment, I don't feel the site inspires confidence or would convince someone that this is the best place to buy or sell a car.
Sorry to be harsh but I feel you've got a long way to go with this particular website. I think unless your styling and functionality are absolutely 100%, then there will be lots of other websites selling cars that will do the job better.
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.