i never used any repellent of any kind, and the only "safety" measure my partner and i used semi-religiously, was bee spray, just so we didn't get stung. as most know, bees just LOVE to set up housekeeping in cars that sit still for any length of time.
A junkyard i used to visit years age had tons of them. It was in the middle of the woods and had bees nest's in a lot of the cars. If you stood still and just looked around you could see them making trips back and forth. Had to see where they are before opening a hood and get big surprise!
It will test your skills running in a junk yard.