OP
Phil
I did the exact same thing, however it was only 1 kipper...we wrapped it in a plastic bag and popped it under the passenger seat of his car, after about a day it started to absolutley stink - he was opening the bonnet and everything didn't have a clue what was going on - took him 5 full days to finally find out what and where it was, and about a further week for the smell to eventually go. Bringing back memories here haha.
I know mechanics who used to empty a 4 pinter of milk under the back seats of customers that annoyed them stinks like puke when it goes off