My moms car (06 300C) has a problem that nobody has been able to diagnose and is getting worse.

The problem is after filling the fuel tank, the car will almost immediately die when started back up. Today it died 3 times after filling up. Got down the road a few miles, and it died repeatedly in traffice. The only time the car has died is after filling up, only when the tank is full or almost full. I can pump the throttle and it will start, but idle very rough. Clean it out and it will be ok, may die again, may not. It was pretty nuts in traffice trying to keep it running.

After the fuel gauge goes down a hair the problem goes away till the next time the car is filled.

It has had this problem for going on 2 years, but today it was very bad.

Ive had the car in two shops (one a chrysler dealership) and they can find anything wrong. Apparently it isnt throwing any codes.

Any ideas?

Thanx in advance for any help or advice.