Updates: My A/C is running great, just in time for summer. I took it to the dealer to get it recharged and they found $7,000 (!!!) worth of stuff to fix. I had them to the A/C and that's it (cost me $3,000 - last time I go to the dealer). They wanted to fix my oil pan leak (actually, it was the oil filter housing gasket) and oil filter leak O-ring leak (really? adding a new o-ring?), new rear tires, 2 new airbags, and a few other things.
Anyways, I replaced the OFHG with a viton one and it seems to not be leaking any more. I also changed my oil and used that fluorescent liqui moly stuff. I shouldn't have any more oil leaks.
I got cheap new rear tires from discount tire. They aren't anything special, but I figure by the time they wear out my front will be gone too. My wheels are covered in road rash so I may just get a square setup and then get decent tires. That's 50K miles down the road (I hope).
I had an error code for high resistance in my left head airbag. I cleaned the connection and plugged it back in and it seems like the code has gone away. Hopefully it stays gone. The left door airbag is throwing a code too for low resistance. I don't know if I'll need a new airbag or not, but I can get them for $50 or so and it's a lot easier to replace so I may just put a new one in there when I put speakers in.
So my goals were to fix all the leaks and get rid of all of my error messages - 1 airbag and replacing the right side headlight washer plunger ought to do it. Then it's just a bunch of little things that need to be repaired and I can move on to cosmetic stuff.
I also got the back up camera working on my Avant 3. The DVR system plugs into the CCD RCA plug, not the DVR plug. Go figure. I'm posting here also in case anyone has the same issue I did. Honestly, I'm starting to wish I'd just gone with an NBT retrofit or something. Avins are so doggone glitchy.
Update on the X5 - no fix for the air suspension yet, but I think it's the control module - $600 :'( and now it needs a new brake vacuum pump. I will probably do that tomorrow.