I wrap a thin solid wire around the the trip lever a few loose winds and embed the peanut butter on the trip lever, even a little underneath. Otherwise they will just lick it clean with no snap. I
I suppose you could put the car up on 4 jack stands and greese the jack stands so the mice/rats couldn't climb up. Or set thejack stands in trays with
oil to make a moat. Be creative. Good luck.
John