Thought I'd drop a few words here seeming there's in general not much activity around here.
S2000 I'm not sure I'm feeling it on this shot. I'm even quite sure what I think is wrong with it, I can't complain about the background on it as you've said the street was busy so I'm not expecting nothing to be there. The colours and everything seem to be fine, must just be matter of personal taste I suppose! But I do like the perspective that leads into the S2000, that's a good spot!
Evo I like both of these shots actually, the first one although the BG is a bit distracting with having two Mini's in it, it seems to work. The DOF as Beerzy said has worked really well on it, it isn't a photoshop blur is it? If not then what lens were you using, if you don't me asking? Overall a nice shot, and something else which caught my eye, the number plate is quite unique as well.
The second Evo shot probably could have done with a little bit of a lower angle as if to be looking up at the car rather than being level to it, in my opinion. You did a nice job of avoiding being caught in the reflection on the side though! I'm not sure whether I'd call the A8 a distraction or not to be honest, without the A8 I'm pretty sure it would look far too empty but on the other hand it does kind of distract you from the main point of the image. Overall, nice.
Mini All three of these shots are good, great background to support the kind of urban gritty look of the car. The two compliment each other well and make the images pleasing on the eye. In terms of composition, I think the first two are better than the last. They just seem more natural in my opinion. Colours are nice in the shots too, glad you didn't make the shots include much more DOF or I think it might have ruined the excellent effect you have there.
Only needed one or two close-up shots to make it a perfect set.
To finish off, I'd like to agree with Beerz. We have all seen your excellent at taking pictures which show off the whole car which are great. However, sometimes take a photograph of a specific area of the area can create some great abstract effects while still showcasing the car. I'm sure you know what I mean, it would be intresting to see you trying something different with the cars as well as still doing the "show the whole car" photos. Hopefully, I'll get see some of them sometime!