Been there done that Albert, the vinyl actually comes off pretty easily, it's the adhesive that separates the men from the boys and the fact you don't want to damage the paint especially the gloss, cause it's reall friggen obvious when it's all done.
Take this advice: After you have removed all the vinyl lettering......then go to a local Paint & Body shop
and ask them for some "PREP-SOLVE"..... the glue will wipe right off...most of the
glue-removers suggested above will damage the paints finish or just smear the glue.
You can also get a good Prep from a carwash/auto detail supplier,
www.washwayUSA.net I think is where I bought my gallon; but just google washway and carwash to find it, good price too, pick up some of their yellow sponges with the fishnet cover while you are at it, you'll need them with the prep remover.
So...a plastic scraper, some prep, a stack of rags, and believe it or not some black plastic (trashbag) is very usefull for sweating off the bulk of it, I wet down the vinyl in 3' areas and slapped a trash bag over it and let it soak for 20 mins. this helped a lot when I started to scrape, then followed with the prep scrub, and followed again with the prep final wipedown.
your paint, your lungs and your hands will thank you buying the right product.
GREENIE on Mike's puter