I've got an '83 BMW 633 CSi and it has started up every time but one, and only broke down on me twice in the three years I've owned it. It has about 98,000 miles on it, and some of the sensors needed to be replaced at 17 years old, which seems pretty good to me. I rode in an E36 (early-mid nineties body style, before the current one) 318i and I still prefer my old Bimmer. I do have to say, though, that the repair costs are quite a bit higher than what you'd expect for 'merican or Japanese cars. Besides that, you'll find yourself wanting to blow tons of money on upgrades too

I bought the car for $2795 and spend about five times that getting it to the perfect condition it's in now. If you buy a BMW, you'll be buying more than just some old car (unless it's a 3-series). You'll get weird smiles from old guys driving SUV's that wish they weren't driving SUV's, and watch the expression on ricer's faces when you smoke them in an "old" car.
Don't listen to what people say about early model BMW's. I read about all of the work BMW put into designing the safety features of my car, including an internal roll bar (which wasn't a federal requirement at the time), a hood that absorbs most of the impact of a crash by hooking into the firewall, crumple zones and much more. It was ahead of its time, and met or exceeded most crash specifications of the time. All in all, you're more likely to avoid an accident in a BMW due to superior braking, handling, and acceleration anyway.
Oh, and Mercedes' are nice too.

Any way you slice it, for eight grand, you're not getting an S500 with 50 airbags. Get a Volvo if safety is that important, but if you want to enjoy a car and know that 99% of the time, you'll walk away from an accident, get a Bimmer.