So, his idea was likely to wear the Dickie coverall over regular clothing. Since I believe he tried to minimize blood spatter, it would be possible for him to drive out of the area and not look particularly blood-stained.
Presuming he put on his killing costume at home (which is not known), then he ought to have taken that Dickie coverall off before getting back in his own car, in his hurried timeline.
He ought to have brought something to put those coveralls in and something to put the black nitrile gloves in (kudos to those of you who guessed he'd have nitrile gloves). Maybe something to put his shoes and socks in. But surely he didn't do this standing out by his car? Doesn't seem he did it in the house.
It's possible he got spooked and got into the car with the kill costume still on his person, in which case I'm optimistic about victim blood remnants being found in the car.
He really would have been better off sinking the Elantra into a nearby lake and claiming it "got away from him" while he was launching a rubber raft or while he was fishing. Naturally, this would require some skill and knowledge about local geography.
I think student housing would have done a thorough vacuuming before re-letting the place, personally. I wish we knew if those hairs were just lying around or whether they came up with a vacuum. No pets are supposed to be there and the fact they only found 1 animal hair is hopeful. I hope it's Murphy's.