Jeoff, the 1/48 scale vehicle market is one of the least populated resources there is in O scale. Very Very few true 1/48 scale vehicles have been manufactured. Most hobbiests are using 1/50 as a fair alternative and the 1/43 as next choice if properly placed on the layout can be a reasonable choice, and there are many to pick from in that scale. Make no mistake 1/43 is too big, but when you using it as a background detail the appearence is ok. 1/50 is available to some extent, but not in a wide spread variety unfortunately.
If some one with deep pocket were to invest in producing a true 1/48 scale vehicle assortment, I suspect there would be endless customers.
Bob