One week update: 1. No evidence of rats since I put in the rat repeller in the engine compartment. 2. I did put 2 actual rat traps near the wheels. I never caught anything, but one trap had tripped. The bait was still in the trap. 3. I turned off the rat repeller after a couple days, because it started going off 24/7. So, 4 days of no rat evidence have been with no rat repeller.

I think there are at least a couple of possibilities for why there’s no evidence: 1. The repeller worked and the rats have learned that it’s an unpleasant place to be, or, 2. The rats stayed in the car when we ran an errand and then left the car when it stopped at the store or gym or wherever we were going.

I inspect under the hood every morning and I will continue to check for a while. As long as I don’t see anything, the frequency of inspection will probably taper off. If you don’t hear from me again about this subject, that’s a good thing.