...been wondering since I've learned about the GP...

One of my cars is also a rare car, 1998 MB C43. Both 1998 and 1999 saw 500 come to the US. In 2000 the E55 was the selection most people chose, and I think the C43 was a special order that year or at least was definitely very limited in numbers released, and only a few hundred were sold to folks here in the US. So there's a fairly limited number of them on the roads.
Yet over the years I must have come across maybe a dozen, maybe more on the roads.
......but I've never seen a GP..... So, where ya all hiding?!
One thing that comes to mind perhaps is I live in the NYC Tri-State area. This wider area (extending to lower New England to a little bit south of NJ), Florida, California, maybe Greater Atlanta area, is where we see the higher concentration of MBs. I kind'a gather that the Minis / GP are spread more evenly through-out the USA? Is this true? Actually, I think I can go look @ a registry to answer that...