[Dzines4SAMP]

You can't set vehicles in an interior unless you create your own interior, and add vehicles in that, or in JernejL's map construction software, if you just go up, you will see those interiors available in GTA:SA (no idea why is it up there). You can edit it (can't delete it), and add your cars, but then you have to find the SetPlayerPos for the player to be TP'ed into the interior from a marker.