I wouldn't have a problem with it. I would rather him do that, and say, I got robbed and stole all the electronics in my house, and stop that car on the same premise.
When I'm delivering computers, I bring all my paper work with me, invoices, estimates, ect. that also include customers names (businesses name if it's being sold to a business), address and phone number. The name for my business is on the invoices along with my name (exactly as it's written on my drivers license and SSC) so there's no mixing and matching.
Would I have a problem if he kept pushing the issue? Of course, but if it was just a simple, "Why are there 5 computers and monitors in the back of your vehicle?)" I'd tell him, and provide the papers to show it, and he let me go, I'd be fine with it, I know he's doing his job, and at least trying to catch people with stolen items. If he wanted me to pull the computers out, or have a K9 search my vehicle, no, I'd have a problem with it.