Maisto also makes on in their "Fifty5s" series. I got some on ebay (after being completely unable to find them for sale at ANY store or my usual Maisto/diecast vendors) and they measure out to close to 1/43 scale, which is compatible with O Gauge (Lionel) trains.
Comparing it to a known size accurately scaled 1/43 car, the proportions are off a good bit. The width and height are close, but it is about 1/2 inch too short. Basically, it's an xB2 but in xB1 proportions. The difference is most noticeable in the nose, which is WAY too short:
(All images found through Google)
Edit: It looks like a caricature version of the B . . .
The REASON very few sell this line is that it is an odd collection of car types and most vendors only want one or 2 of the models and have NO use for the rest. As the cases come mixed, they will have ones they can't move, so they don't bother at all.
I was offered several chances to by a case, but declined.
The case would be a completely random mix of:
2009 Nissan 370Z
1972 Datsun 510
1985 Toyota Tacoma
Mistsubishi Lancer Evolution
1975 Datsun Truck 620
Scion xB
Few vendors want more than half of those, and they are in a odd scale/proportion for most collectors.
