I have a water leak in the rear corner of my driver's side rear window. I've given it a quick fix just to keep the water out while I drive it, but I was wondering if this was a common problem and if anyone could give me some tips on repairing it.

If your talking about the rear window yes it is very common. If it is leaking you'll normally see it in the trunk. Very poor design with no draining. Only good way to fix it would be to remove the back glass, clean-up the channel, remove or treat any rust, repair any pitting or holes with "All Metal" or a similar product so that you have a nice smooth suface, then protect with either an epoxy paint or Por15 type product. Reinstall the glass paying close attention to the sealing of the glass to the channel. Because of the design water will always get trapped in the lower channel. The epoxy or Por15 should keep the water from getting to the channel and corroding the metal again. Mike