I think the system as it stands encourages PC interaction. If you obfuscate things too much, people will ask for automated NPC mechanics to help deal with demand.
That said, I think a layer of obfuscation accompanied by the damaged vehicle messaging that has been implemented may have the desired effect but I would be extremely cautious about skill gating vehicles as they already feature a number of balance issues.
BUT.
I think evaluate to look at the inner parts should only be done if you're 1. Authorized on the vehicle 2. In a mechanic's workplace. And if you aren't in either of those, then it should be considered wildly suspicious because some of those parts you're going to need to be lifting up hoods or leaning/digging in incredibly close that should make the ambient population wonder why that's happening.