For those finding this thread in the future, since OP didn't say how he solved it:
Add to Description.ext
wreckLimit = 1;
wreckRemovalMinTime = 60; //seconds
wreckRemovalMaxTime = 60; //seconds
wreckLimit: Limit of total wrecks at any time.
wreckRemovalMinTime: Remove all wrecks that have existed longer than this when wreckLimit is breached.
wreckRemovalMaxTime: Maximum time a wreck can remain on the ground even when wreckLimit has not been reached.
https://community.bistudio.com/wiki/Description.ext