If you don’t want to mess around with headlight-lamps, just load up the back of your vehicle with Metal Tanks (which you can get by remOving gas and water tanks from pretty much every vehicle) and Pipes (which you get easily by Smashing display racks in stores). One pipe and one tank makes a Wood Stove. Wood Stoves don’t make smoke and their fire won’t spread to adjacent squares, so they’re safe for indoor use. Despite being called Wood Stoves they will burn anything remotely flammable, and burn for hours on next to no fuel. They cast enough light to fill a medium sized room. One or two should adequately light your garage, and they’re useful for crafting and trash disposal, too.