Thank you guys for advise, I am very frustrated at this point. I was hoping replacing the rear switch would fix the problem. I can do stuff around the house, but I am no mechanic - i.e. I have no testing equipment or specialized tools. I was considering detaching the arm once I saw how the mechanics work, however, I did not see an easy way to do it without potentially breaking the blue lever. I was also thinking about replacing the VCM, but there are 2 issues: 1. not easy access to it, I think I would have to remove more than the plastic cover I already removed (unless you suggest otherwise); 2. dealer will not take the part back once it's sold (at least that's what they told me about the switch). I am reluctant to keep buying parts without having a good chance to fix the problem. Lastly, I was also thinking about the vac leak, especially since the front air now only comes through the defrost mode, as suggested by other members. Again, not being a mechanic, I do not know where to begin to test for a leak without some sort of tester/meter I don't have and proper instructions. If you guys believe the front and rear HVAC problems are related and there is a common fix, please let me know. I took it to the dealer for estimate, they quoted me $900 to fix rear AC issue; I took it than to independent mechanic who told me he will fix it for $400. I did not think it should be that expensive. Any help is truly appreciated. | 
