Sounds like you are using a dealership that has no talent with electronics. These cars have 9 computers on board and an hour with a competent electronics technician using the Chrysler StarScan technology will fix most of the issues you are having.
I have had 3 of the LX cars - a 300C; a Magnum R/T and a 300CSRT8. Not one has ever let me down and I have a great service tech who gets the gremlins out.
Now, mind you, those that know me, know that I really baby my rides . . .
