The intake boots on my 1600 DP Beetle motor were cracking. What drew my attention to it was the gas and shmutz around the gaskets. The original parts require quite a bit of disassembly to replace, but EMPI makes a split boot kit that can be swapped in about 20 minutes. The kit is available online for about $15.
You can see one of the cracks here:
Remove the hose clamps first.
Then cut them off with a razor.
Fit the new ones on.
Tighten the hose clamps and you are done. You may ask why are the hose clamps oriented that way? Well that is to avoid the risk of the sharp end of the clamp cutting through the plug wires or fuel line.