Wet weather gremlins

[scwten13]

I have a 2001 4.4 sport, 88k miles. I washed it in a car wash, the wand type, once with no problems. The next time I left it running and a few miles down the road it was doing wierd things; radio would turn off and on, it felt like the ABS was activating, then it stalled altogether in traffic. I put it neutral while still rolling and it started right up and had no more problems. The other day I drove it after some rain. Same list of problems, but this time "self leveling not working" type notice came up on the MID. It stalled again, again it restarted but I had to come to a complete stop and try twice. No problems the rest of the trip. Anybody else have these problems and know of a fix? BMW NA said they don't have a recall or any info.