Seem a bit washed out mate, probably due to you shooting into the sun?
If the sun is out like it appears to be in these shots you need to think about your angles and position yourself so that you aren't directly shooting into it.
I hate shooting in the sun whens it's really harsh, but other than that some of the cars look nice, love my RS ones.
I will be working the RSOC National Day at Rockingham this year with a company shooting all day