VW Passat dashboard lights problem. Please Help!

Hi, i'm having a bit of trouble with my Passat and wondered if anyone can help. Its a 55 Passat 1.9tdi and i've had it 10 months. The parking break sensor light comes on and it goes into a limp mode (looses power and starts rolling), then just after the PBS light comes on, the esp light comes on and another light thats 2 squiggly lines. At this point the accelerator doesnt work but noticed if you put your foot down on the clutch and rev a lot it kicks back in. I've noticed that this problem only happens when we've had heavy rain, or once when I went through a drive through car wash, came out and it all happened again. With winter coming this problem is only going to get worse!!
I've taken it to a garage and so far payed out over £600 to try and get this problem sorted, 1st they hooked it up to a computer and said they've gone through some codes and reset it. . . . couple of days later light came on. Next they said its to do with a rear sensor that was damaged so replaced it. . . . couple of days later light comes back on.
I love my car when this fault isn't happening but right now im starting to hate it!!
Any ideas??
Thanks very much.
Asked Oct 26, 2013

TIP: If it's not your answer to this question, please click "Leave a Comment" button under the question to communicate with the question owner.