I will add to slantsixdan's post above by saying I use those Philips X-Treme red 1157s and their X-Treme white 1156s in one of my older vehicles, and they work righteously.
Buy 'em up now, folks, while you still can; they're being discontinued. Philips now has two lines of cheaper, inferior LED bulb on the market instead...neither of which puts out forward light, so they're useless for the fresnel-optic lamps on many of our old cars, as described in post № 80 of this thread. :-(
