I have not bought anything through them but I have sold a vehicle to them. Definitely do what you said and have someone very knowledgeable check the vehicle thoroughly because Carvana surely does not when they purchase inventory. When they purchased my vehicle they showed up handed me a check and asked for the keys started the vehicle and hooked a tow truck up to it. I know there is a refurbishing process the vehicles go through etc but there are plenty of reviews online of vehicles being delivered with the check engine light already on or issues popping up shortly after delivery. If anything at all is out of sorts return that thing during the trial period. They will take it back no questions asked.