Here is a handy resource for people making sponsorship signage for their tracks. recreations of logos from a gazillion brands around the world. it'll save you some time, if you have a program that can open some diverse file formats. don't forget to seek the express permission of the copyright holders before using them though... http://www.brandsoftheworld.com/ i suppose a google image search for '[insert brand name] logo' would be another way to do it. for the sake of your tracks, you might want to add a bit of noise and 'grubby-ness' and do some tonal adjustment, or other tricks, so it looks more real.