Bertfish
Throw bread on me
Police Officers and State Troopers are usually not permitted to pull MILES/CJIS information for citizens on request.
That does not include information provided at accident scenes or so that a complainant can obtain a warrant or DCS, but generally, you can't just ask an officer to run and provide info off that system.
They should be able to tell you the proper procedure for requesting you registrations off the MGUN system, (if that is what they still call it these days). My guess, though I may be wrong, is that MSP will provide you with a procedure to get what you want.
I would certainly hope that the good folks at MSP would do exactly as you describe. I don't see any way that any agency could have the authority to deny you information about yourself.