My CTT is a good example of the issues you get with kessy. (It is identical to the Touareg system by the way).

Only one of the four rubber buttons on the door handles actually locks the doors.
Three handle sensors work correctly to unlock the doors.
One you have to pull on the handle to get it to wake up and unlock.
One other handle is very sensitive and, if you walk past it with the key in your pocket having locked the doors, it unlocks again.
if I do hold the handle to unlock the car it unlocks the rear doors but not the front doors. You need to use a front handle for that. But if you start with a front it unlocks all four.

So I just use the buttons on the key fob. Press to lock. Press to unlock. Works like a charm.
i think four new handles would probably fix it but at £150 each and a complete dismantling the door I can live without it.

 

My '06 Turbo S door system still works fine at 190K