Can you waterproof the computer?
 

My 1997 base 986 has the water under the seat problem many have described. Poured water in from every angle on the roof down the sides etc and can't seem to pinpoint how its getting there or why it won't drain when it does.

Had a crazy thought that maybe I could use some heavy plastic bag with wholes on the top to cover the computer/board. Do you think that would help or do more harm than good?

I bought one of these boxes haven't installed it yet. I got a plastic Tupperware thing and put the computer in that for now.

I installed one of those. Easy. I figured it was cheap insurance.

I also installed one of these. When I installed it at 107k miles last year my immobilizer board looked like new. Cheap insurance.

Did you have any issues after installing?

Issues........?
 

...Negative, Ghostrider.

No issues after install.

Wet Box
 

After I lost an immobilizer in my red Boxster I fitted the ECUDOCTORs plastic case to all three off mine, and also (God forbid!) drilled holes in the floorboards to allow water to drain out. No further immobilizer damage, even though my silver Box still leaks and soaks the carpet.