My MPi was sold new by SMC Rover of Slough, one of (if not the) biggest Rover dealers in the country at the time. It was first registered on 1st March 1999 (the first day of the 'T' registration) by the dealer itself, so I think it was a dealer demonstrator. It has some expensive options on it so that seems likely. In the wallet with service book etc, there is still an original dealer membership card (giving the owner free servicing) with the first private owner's name on it, and a business card for the sales rep that sold the car.
My local dealership and where I used to spend a LOT of time waiting at the parts desk. In fact I probably sat in your car while waiting a few times! I don't know about them being the biggest dealer but they did have one of if not the highest turnover of Minis in the country at the time your car was born. I don't remember them having a blue regular Mini demonstrator to drive but they had a blue one on the shop floor for a while and a Volcano Orange one. I was there a lot in '99 as we started our first rebuild of the car we still have that summer. They had a Paul Smith demonstrator that they were trying to push on us once, my girlfriend (now wife) got so close to buying it. She filled in the finance forms and everything but chickened out during the cooling off period. We were still kids and it seemed like a huge financial commitment. Does your car have a full length sunroof? All the ones they used to have in the showroom had a Webasto I seem to remember. Does it have zip decals?
It has neither, but then when I bought it the side decals were missing so the zip decal could have been fitted new. It has the walnut door cappings, leather cooper seats and sports pack.