Well, if you must do something AND you're willing to take the consequences:

* fast-drying epoxy or superglue in all the locks. Gorilla Glue would also work. (Also good for gas caps.)

* you can buy doe, fox, and other urines in a hunting store, like I mentioned before. Also skunk.

* lots of Liquid Joy dishwashing detergent in the gas.

* a tight-fitting paper cup over the exhaust pipe.

* a condom full of dog poop up the exhaust pipe until it falls into the muffler.

* a road-killed skunk wedged up into the engine block.

* a piece of rubber carefully laid across the engine.

Bad karma and worse will fall upon you if you do any of these things.