I'd caution against rechargeables for your vehicle light because they'll tend to lead to the very problem you just experienced: dead batteries! Most rechargeable chemistries tend to self-discharge over time, so the longer you leave them in there, the more likely it is that they'll be depleted when you need them most. Since you only use the car lights once in a blue moon - but when you do, you really need them to work - I'd consider buying something that takes lithium batteries, which can sit for years and still be ready to power the light.
That said, are you looking for something with a lot of brightness - a "spotting" light - or something with extended runtime for emergencies? I generally have a Surefire 6P and a Fenix P3D in my cars. The Fenix has a loooong runtime on low, so if you're ever caught out for a night, you'll have illumination the entire time. The SF is an incan, which - for me at least - better cuts through fog and has a more tightly focused beam. In any case, with a little more info on what you want the light to do, I'm sure CPF will be able to provide you with a lot of great suggestions!
- FITP