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