Passat-water damage to car computer

My Passat 2000 sedan (off warranty) would not start on a recent morning after a rainy night. My local mechanic’s assessment was water damage via water coming thru the firewall near the battery, going under the cabin rugs, and damaging the car computer under the driver’s seat.

A quick check on the Internet demonstrated that many other people with Passat’s and Audi’s have eperienced this problem. Volkswagon is denying that this is a design flaw, despite having instituted some change in the design of the firewall ( I don’t have the specifics here)-according to my mechanic. I have never received any recall notice advising me of the problem if left uncorrected.

The internet discussion of this problem also noted that more than one VW dealership has suggested that owners who experienced this problem should pay for the damage via their car insurance. My deductible is too high to be of help here, but the primary issue is that this is a VW design flaw.

My questions:

-what is the appropriate fix for this problem so that it doesn’t happen again if I repair the damage?

-what successful strategies have been used to get Volkswagon to do the responsible thing here;

-does anyone have any strong opinions about getting a used computer vs new computer installed?

-what consumer or govt agencies could I report this to in the attempt to put pressure on Volkswagon for reimbursement?

Every car has design flaws. There has never been a vehicle built by anyone that was fault-free.
A problem with a vehicle, even one with a design flaw, does not mean that it will ever, or should be, part of a recall.
There is a recall somewhat related to your problem but does not apply to your year model vehicle.

The vehicle is 8 years old and have you ever had the air plenum, and sunroof drains if so equipped, cleaned out? The same could be said about the evaporator drain hose. Has that ever been inspected and cleaned if necessary?
Has your mechanic even checked these drains?
Dirt, leaves, etc. can clog the drains and cause water to enter the car rather than exit to the ground.

Computers seldom go bad so I would not have a problem with taking a chance on a used one if the price is right.
You can file a complaint with the NHTSA but unless there is a legitimate design flaw, as compared to clogged drains which are not, you’re not likely going to go anywhere with this.

You can contact the VW regional office and they MIGHT do some kind of good-will warranty for you. It’s a coin flip.
Engine computers are under emissions warranty for 8 years/80k miles. Since the car was probably built in '99 it could be a warrantable issue IF the mileage is under 80k and IF the delivery date when the car was first sold is after the present time.