Loraffe Under Hood Rodent Repeller Ultrasonic Rat Repellent Mice Deterrent with Ultrasonic Wave and LED Flashlight, Pest Control for 12V 24V Vehicle Auto Truck RV, Keep Animal from Chewing Car Wiring https://www.amazon.com/dp/B07JG4V1ZP/ref=cm_sw_r_apan_glt_i_EGF1XC18FM86JHYYJHN7?_encoding=UTF8&psc=1
I have a 12vdc ultrasonic repeller with strobing LEDs under the hood (mind you it's a parasitic load on the 12V battery, but I park in a garage at night with the car plugged in).
I also have a large sonic pest repeller in the garage aimed at the area under the car, that one runs on 120VAC.
Had a rodent concern two winters ago in the garage but these measures, along with several cans worth on expanding foam sealant in every slight nook or cranny of the garage, seems to have taken care of it.
The underhood repeller is this one:
Loraffe Under Hood Rodent Repeller Ultrasonic Rat Repellent Mice Deterrent with Ultrasonic Wave and LED Flashlight, Pest Control for 12V 24V Vehicle Auto Truck RV, Keep Animal from Chewing Car Wiring https://www.amazon.com/dp/B07JG4V1ZP/ref=cm_sw_r_awdo_navT_g_VKZ4PQ6HS6P5SCVBXGB8
someone I know had a squirrel problem and this worked. It's not hard to install. There's endless amounts of different ones so I suggest researching a little more on the particular brand. automotive rodent repeller