can't put freon in a.c due to electrical issues

I really can't explain exactly what the electrical problem is. Every auto place I have taken it to, doesn't have a clue either!! My car would not start some days and other days, no problems. Bought a new battery,(interstate) thought that was the problem. Well, is was not!! It has been on Diagnostic machines 3 times.COST ME A FORTUNE!!!! All I ever get is, we can not figure out what is causing this.The Auto stations I have taken it to,are very good, reputable company's. Firestone told me to go to GRAYBEAL AUTO now. I, do believe it is a problem from NISSAN CORP. I think I got a defective car. My 6 CD player just quit one day also. My car was only 3 yrs. old!! My DOME lights come on sometimes, and, sometimes they don't.I guess my next step is to contact NISSAN HEADQUARTERS, WHICH, will be my 5th attempt. I REALLY love my car!! It has been VERY GOOD to me! EXCEPT for the ELECTRICAL ISSUES. And YES, My car does ONLY have 45,324 miles on it. .SO, Someone PLEASE, send me in the right direction!!!!