...and dryer sheets under the hood too. Engine compartment has easy access from the underside...lots of flat places to build a nest...and LOTS of wire to chew on.
I did, once. Had the door open, so it launched them down the driveway. Now I have a couple strips of yellow safety tape wire tied to them. The tape hangs out the end, as a reminder, or as a marker to make them easier to find down the driveway.
I've seen mice make nests out of dryer sheets, so while their odor may keep mice away for a short period of time, once the smell dissipates they aren't going to help. I've also seen them eat bars of Irish Spring soap - same deal.
They should be fine. I have stored my cars many different ways. Jack stands, Backyard Buddy rollers and just on the tires. All those ways worked for me. It depends on your circumstances.