I have a 2004 MW. Having used my key fob to open the doors, I found that the tailgate was still locked. After twenty seconds or so I heard the lock operate, and it WAS open. Then it locked, and then opened. On my drive home ( ten minutes) I could hear the tailgate lock continuously operating, and the 'door open' light was on.
Has anyone experienced this problem. Is there a cure for it? It is very annoying.

Start with removing the switch with an old creditcard.
Might be the microswitch getting stuck. I cleaned mine with electrical contactcleaner, clicked the two plastic halves back together, cleaned the rubber surround with some vaseline and click the reassembled switch back in the handle. Works perfectly for my car.
On my sons MW the microswitch was dead so we replaced the switch with a new one (€ 65) from the friendly neighbourhood dealer.

gr J

Thank's for that A3. Did as you suggested and found the switch full of water. Dried it out and sprayed with WD 40. Works a treat now. Hopefully no more problems. Thank's Again.

Did you apply some vaseline on the rubber? That'll help with keeping the rubber flexible and with sealing better.
Glad it worked.

gr J

Mine satrted doing the same on Saturday a little, then did it a lot yesterday, after I'd done 100 miles in mucky weather. Hasn;t done it again today (yet) - I'll give it a clean over the next day or two

Jeroen - you say remove it with a credit card - does it just prise out?

Yes it does.

gr J