Ok let me think, I use photoshop to 'virtual tune' cars so i'm on lots of sites for that, the main one being http://digimods.e-visionit.co.uk/

The most recent forum I have joined is http://www.cleaned.be/forum/index.php? lots of cool cars on there you should check it out.

To be perfectly honest I have no clue how many forums I have joined.