do it! its a piece o piss to do, dunno if you need a different slam panel but its easy to change, and someone will buy the jetta front.
check your doorcards are not rotten at the bottoms, pull em off and inspect the membrane on the door.
this needs to be pretty much watertight mk2 s are designed to let water in the doors. also make sure the drainholes are clear at the very bottom of the doors so the water can drain away.
check the door shut seals are in good nick too and the roof gutters as this can also be a problem.
alsso the drainholes from the sunroof can fill with crap and you need something like a wire coat hanger to clean them.
other than that it could be windscreen seal? heater box? the panel under the bonnet where the wiper mech is?
dont worry tho, most mk2 owners have these problems, including me!
