I can feel for you - i've only left my car with people to do things a few times, detailing, alarm stuff, audio etc... i always check my odo before hadning it over and say 'you dont need to drive it anywhere besides in and out of hte shop do you' they always say no... that way i can use that against them if they have... sounds like what you do as well....
86ks is alot, that would be 2 hours of driving, i could get over say 5ks for road testing etc.. but 86ks, i would of gone SKITZ