Ruined Vehicles are being counted as live (touched, no lifetime assets) and as a result Vehicle events believe they have spawned to the nominal value or reached the max value and spawn no more. However a quick recon of the server fails to yield any vehicles at default spawns or found crashed on the road or stashed in a barn. The issue appears to be the CLE is counting ruined cars removed from the server as still being live / touched vehicles and thus still counting them in the no lifetime bucket.

issue first reported via private bug report T182296. I have never heard an update on it and while the severity is minor, its a major impact to vehicles and their ongoing availability. The only way to provide more cars is to wipe via event off and on or via the ignored list, which wipes all vehicles even those in use by players.