only way to really get caught is to A: get yourself in some sort of trouble ( break the law elsewhere ie steal a car or something silly like that )
B: by talking about it, every person you tell or knows that it is there, is 1 more person that has to go on your suspect list if anything goes wrong,
C: by someone getting sus by the smell, carbon filters are fine for this, just rig it to the end of you exhaust, they are affordable and effective you local hydro shop should have some.
apart from that if you keep it low key and sensible, you should have no troubles at all.