Crashing does cause issues with vehicles and drones (and your save game itself). If you crash (and are on PC), do NOT load your game until you replace the saves with the backup saves, or at least make a copy of your backup saves in case you do have any problems caused by the crash. Once you load your game, your backups will be replaced and will be of no use.
Regarding vehicles, I have never seen a vehicle completely lost. It will be found somewhere on the path you were on when the game crashed. Look at your log or the console and it will show you the location of all vehicles about every 5 minutes or so. Just go there to find them.
For drones, it's trickier. Drones can be lost for good, though not always. The log/console only shows the drone location when you first load the game (right about the time you see your character's hand appear). If the coordinates are numbers, you can go there and find your drone. If they are (NaN, NaN, NaN), then it's lost for good and you'll need to use the jd clear command to clear the drone from your ownership so you can place a new one. If that doesn't work, you'll need to delete the two drone files in your save and then use jd clear. There are rare instances when a drone will return to you later, even if it didn't have real coordinates. In one case, I had 2 drones following me around until I picked one of them up. That was fun since it gave double storage. Heh. But that's very rare.