Spray mice repellant

Awhile ago the DW watched a video on some sort of spray for the unnderside and suspension of RV's supposed to repel mice. Naturally I was sure I had saved the info but.... Anybody know of such?

I am thinking of using a fox urine spray. At home I park the MH on aluminum flashing which does not give them enough traction to climb on the tires. Great at home but not so much while traveling.