Looks like it will be where the air intake first enters the engine bay itself, through the inner gaurd panel, if its the same as mine, that part of the pipe has only 2 bolts on one side to retain the pipe, the normal/easy thing to do, is use sealant in that area to prevent leaking, it looks like only gasket goo has been used, Sikaflex would have been a much better and stronger choice.

The problem is, that even with a good dose of Sikaflex, the first time you change the air cleaner element, you can disturb the seal by moving the pipe just a little, when i fitted my snorkel, i also added 2 more bolts with big washers to retain the pipe all the way around (as well as a heap of Sikaflex)