Hmm, that sounds awfully like the common Passat problem, water leaks in through plenum chamber and gets into the Comfort Control Module (controls, alarm, electric windows, drains battery sometimes), and basically it's where the front passenger seat is, all the water comes in, goes to the lowest point and erodes the cables, and causes all the issues your explaining. So first thing I'd do is get rid of the water, strip what you can from the back, get someone inside then put a hose on the back and find the cause of the issue. I had the plenum chamber problem, also had water leaking through the door cards Like I said, this is common on passats, but don't know if Lupos even have CCM, or where they are :/ http://www.headfuzz.co.uk/vw_ccm have a look there at the problem