^on business cards, it's true that the cars wouldn't fit in the letters, but on a tshirt it shouldn't be a problem... if you put "extreme" on one line in large letters, and "effects below it in slightly larger letters, then you can put pretty much anything in the letters... and having the pictures of the mustangs in the letters would be significant, since you specialize in mustang performance, then having one or more mustangs in your logo makes good business sense... especially with tshirts, the detail available with a silkscreened tshirt is pretty high, so it would look nice...Those do look good. I can see if we can use the first one if the letter could be made less "bubbly" if that makes sense.
Also the logo with the cars inside of them also looks kick ass, but I don't think it would look good as an official logo. After all it has to be transfered to business cards, T-shirts and other things like that. But for various uses on the site it would look damn nice.
Keep it up if you feel like it. Maybe we can use it in the upcomming calender!