For wash method:
http://video.google.com/videoplay?docid=7598756069207401372#
*Some folks double up on the grit guards for a 2x4 method
For products:
Shops
A second nod to Autogeek.net/
DetailedImage.com/
DetailersDomain.com/
Products
Car wash
ONR
Chemical Guys Citrus Wash & Gloss
Wax...
Another UD grad living in Columbus. This place was exactly what I was looking for when I was redoing my garage floor. It also gave me some great ideas for storage and general setup.
I couldn't use a laser level or chalk line as my garage walls have too much bow in'em. I ended up using: my dad, his old carpenters square, a level, a little beer, and a lot of cussing. It was the best time with my dad I never want to have again.
I had some paint on my garage floor that wouldn't succumb to a power washing. I ended up buying some Behr paint stripper from Home Depot. It was pricey, but it did the trick. I also ended up with too much extra product for my needs, and the rest ended up going to the local household hazardous...
Use a no rinse car wash and make it a non issue!
http://www.griotsgarage.com/product/car+care/car+washing/car+cleaners/spray-on+car+wash%2C+35+ounces.do
http://www.autogeek.net/optimum-no-rinse.html
Maybe this? Today is the fifth day of cleaning the garage in a home I just purchased, and it worked extremely well on removing unknown paints throughout the garage.