some pics I could find in a hurry some are worked on some not...if your car is in shade, make sure the background is in shade, same for if its in sun. Like I get told at work - find your background then place your subject in the background.
1. Industrial area...on a weekend should be deserted so you can get nice clean backgrounds
2. East Perth - the little area down near lamonts as seen before. If it's good enough for half the weddings shot each weekend its good enough for your car!
3. Go bush and find some little side road, gravel shoulder
4. Interesting architecture somewhere or complimetary colours to your car
5. Old deserted buildings although this one opp. Ascot is being demolished atm
6. Boat ramps - that way you get lots of sky, simple background therefore more focus on the car
7. Colours that go with the car once again. Clean and simple background.