I thought that you might find this little snippet to be of interest.
Before the official launch of the Omega B, GM ran several thousand identical cars through the factory in Russelsheim as a final bedding in operation for the factory.
These cars were all exactly the same, 2.5 V6 manual saloons in Aubergine (Metallic purple). They were "CD" spec but without alloys. When I say identical, one in every 4 cars was a Vauxhall - which was the approximate sales mix at the time.
These cars were all registered to the national sales companies, i.e. Vauxhall in the UK, and all used for evaluation by staff, as company cars, and to associate companies such as Delco, GMAC, EDS etc. I worked for one of these companies at the time and was allocated one. It was an L reg, but I cant recall exactly when I got it, maybe early 1994.
What I do recall was that we wern't allowed to take it anywhere near a dealership as it was a month or 2 before launch and the dealers hadn't done any training at the time. Mine went wrong with an alternator failure after a few weeks and was carted off never to be seen again.
So, if you do see a met purple L reg sort of CD spec then you will know a bit about its origin. I still see the odd one around from time to time, as there were several hundred in the UK.
Hope that was of interest .........
Rob