[MattTucker]

I haven't personally tried it before but logical thinking, trying to respawn 1500+ vehicles all at once is a bit rather too much? creating them on server start would be fine as there'd be no players, but having players on the server would definitely cause some lag.

Unless you've got a very good VPS/hosting service then sure whatever floats your boat, but personally I'd try to switch it up. (Also check your MAX_VEHICLES)