'95 E320 w124 reverse gear gone (after car wash?)
 

My car has 94K on it and suddenly after a car wash it has lost its reverse gear. Going forward is strong shifting but it only has about 2% grip in reverse.

Until then I had only driven it a little in the last week, and it had sat mostly for a couple months. The reverse used to take a second to engage but then fine.

My plastic cover on the engine block came off earlier. COuld it be that wetness from a car wash could have caused this? I also had cleared the drains from the windshield/firewall area with a hose a week ago.

Any one with a same problem that got fixed without an overhaul?