You can just wrench it and it will say 'So and so' or 'BL_ID: XXYY' does not trust you enough to do that.
V8 had an add-on called the ban hammer, which could tell you who planted a brick regardless of whether or not you had their build/full trust. If someone could remake that, than you could simply hit the vehicle spawn with it.
Could turn out that someone with your trust is spamming vehicles. If that's the case, wrench won't necessarily help you.