I've had a problem with my AC refridgerant leaking out of the system. Not sure where exactly it's leaking yet but I'm keeping an eye on it. You can re-charge the AC with one of those R134a recharge kits at autozone or advanced auto parts - $20. Real easy. The low side service port of your Baja's AC is up close to the firewall - real easy to see and get to; it's got a blue cap on it.
The trick is to pull back on those AC 134A recharge kits and push it on the line good and hard. When seating it on mine, I pushed the aluminum line back at least an inch for it to seat in properly.
In my experience, the most common place for an automotive AC system to leak will be around the compressor - usually a gasket that's leaking either on the high or low side. You can buy a UV-light dye kit or clean the lines and areas around the compressor real real clean and check every now and then for an oily dirty buildup somewhere. If you see a spot that looks like dirt accumulated around oil - your leak is very close to that spot. It's refridgerant oil leaking out with your refridgerant. Don't worry if you've lost some oil though - it's usually not that big of a deal.