I have no doubt it is the contacts on your car but I have had problems with the new cars having bad ground cables. Especially the ones with the battery in the trunk like the Chargers.

If you suspect it to be a bad ground cable it is easy to diagnose. Put a Jumper cable from a good ground, like the shock tower ground, to the engine on a metal bracket, like the Alternator or power steering. If the problem goes away your set. Often the ground from the body to the engine is behind the engine. It gets corroded easily and isn't easy to see.

Just food for thought on some of the newer stuff with tiny ground wires.