It's tight. I have to agree with Justin on this one. The battery cover has to be pushed between the lower battery cover and the snorkle.
If you look at Delvi's pic BELOW, there is NO room between the snorkle and the side of the lower battery cover. You can see that they touch. Mine is like that as well.
The battery cover doesn't latch normally because it's squashed in there. But if that doesn't bother you, then you don't have to trim anything.
Clearly, the TDI is going to be the hardest vehicle to fit this thing.
On a pre 2002, the older batter box cover design is different. I don't think there is as much interference with the older style cover.
If one were to elongate the battery tray holes, then you could steal 1/4 of an inch towards the engine which would help. If it doesn't rain tomorrow, I think I may try modifying the battery tray holes.
The other option is to remove the washers of the 4 bolts for the battery tray, and drill new holes next to the original holes. This would move the tray over a bit as well.
Delvi, does your battery cover fit like normal? Or is it mis-aligned because everything is tight?
Still, a good mod.