In the latest Roundell Issue in Tech Talk, look on page 107. There is a question regarding a flooded DME. According the Tech Talk, cars built after 6/94 had the updated drainage system, that protected the DME from flooding.
If your car (E36) was built prior to that, the modification can be done using BMW service bulletin 41 03 93. 1.5 hours labor.
For me, one less thing to worry about- 11/94 build
