Did l screw up ?

I don't think so. Not many anyway. They are actually really hard to find now a days Noone around here even carrys them you have to get them online. When I was a teenager you could buy them at Walmart target big lots etc. We even had a hobby / rc toy shop in town that had tons of them even had accessories kits you could buy for like aftermarket rims and such. I haven't seen a store like that in close to 20 years.
Hobby Lobby is the only brick & mortar store that I know of the still sells plastic model kits.