If it's headlamps you're interested in, it's headlamps I've got...Petzls, Princeton Techs, Rayovac Adventure Lites, and many more...
For working on your automobile I'd reccomend a Princeton VorTech/Predator Pro 4AA incan. When I'm working on my car it's nice to have a beam that can shine up into dark places, and most LED's just don't cut it, especially if you're working during daylight hours. If you have your heart set on LED's, The Princeton Tech Matrix is by far, the most sturdy headlamp that I've seen, but it's not as bright as some of the others (Lightwave, BD Moonlight, etc.) The Matrix also comes with a bright incan. bulb too, while not nearly as bright as the VorTech, is still respectable. Lots to choose from these days!
Cheers!