On page 5 of its 2005 Second edition catalog (which came out near the end of K-Line) the company announced seven new Superstreets vehicles. As far as I know, only two were ever produced - the school bus, which is a very nice model - exactly 1:48 scale adn very accurate except for length, and the postal van. I'm fairly certain from studying the pictures in the catalog carefully that several if not all were just mockups without motors at the time, and that some of the side windows were photo-shopped. I have searched for the other five, particularly the K899-139 Police Cruiser Camaro in the upper right corner, since 2005, but never found any of them. Legacy K-Line websites list them as being in the catalog, but that's it, and places like Western Depot that specialize in K-Line don't and say they never did carry it. I've never seen any of them on e-bay.
Anyway, here is that Camaro Police Cruiser, as far as I know the only K899-139 in existence. I made this the way K-Line clearly intended to make their version: by taking their own product (K94990 - a diecast 1982 Camaro) and mounting it on the a shortened (3/4") chassis as used in the Superstreets vintage truck (By looking at the wheels and the underbody profile in the catalog pictures it's possible to tell which of the various 'Streets chassis K-Line intended to use for each vehicle. Here it is, with the policeman driver figure, as advertised. I actually don't know if the NYPD ever had any Camaro cruisers, but that is sort of beside the point. It looks good and I have this in my collection now. video after the stills. If anyone else wants to do this, the conversion is simple requiring no modification of the diecast car, which is available on Western Depot for $3.95 - last I checked they listed "more than 12" in stock.
Edit added after: The car disappears for a few seconds at the end of main street but comes back around and down the other lane. In this video it is running at a pretty high scale speed (scale 50-55 mph): I did not install an electronic flywheel in this car as there would not have been room for it and the police figure, etc., and I really don't intend to run it that much. Folks interested in seeing what I mean about stock 'Streets cars not running smoothly slowly, note how this car stutters at around 22 seconds: even at these speeds this particular chassis - not one of the best but only a bit worse than average - won't run smoothly below these speeds.