If you get a motorbike and shoot it you can damage it. Now i have no clue if other peoples vehicles can be damaged in the same way, but ive been told it needs to be reported so im here doing that.
my flak-moped is always getting damaged by some random means, my companion stepped in front of me once and my flak-moped went flying into the sky, like something from Apollo 13 
lol, i carry repair kits with me, or I just drive the flak-moped with gasoline & repairs creation when I need some, that flak-moped goes everywhere I go
even in multiplayer, some meanies are blowing up my flakmoped on purpose 
, how mean people can be, meanies, fine, blow it up, I only have 1000 repair kits that I can make using the very thing you destroyed, because the crafting still works on there regardless to how many bullets you shot at it, i’ll just throw snowballs at you buddie 
meanies
I realise this is not intentional but I’m using it as a means to determine basic weapon damage with minimal faff, so I’d quite happily let it stay this way
You can also damage your own motorbikes, i believe its intended.