1998 Chrysler Sebring HELP ME PLEASE

My car has only 50K miles on it and about 6 months ago someone backe into my font end. I had an autobody place the repaired damage and I picked it up. Problem happened almost immedeatly, when It rains the car won't start but once its dry out it runs perfectly. I have had the car in and out of shop for 6 months and have had the distriutor cap to silinod replaced and nothing seems to work. I thought it might be electrical, however, the fact it starts and runs perfect, make me puzzled. I also replaced the fuel filter wires, plugs, battery, etc. So the simple of this problem is that when it rains it doesn't start and when it dries out, It is perfect. I also have had it hooked up to a diagnsting machine and It comes back fine. No troule. What am I or for that fact the auto mechanics not seeing. Is it a wire that when wet, no start and when dry runs fine? Do you know anyone with the same make and model have this type of problem? One more thing, I place a tarp on the engine when I know It's going to rain. Could the drainage that come down from the windshield seep into the front part of the engine cause this problem
Please help I haven't had the use of my car in 5 months and I have had to pay an extrodinarily amount of money to mechanics that keep giving my car back with the same problem, but I still have to pay for the work or lack of.
Thanks
Michael