not sure if thats a reflection down the side or someones kicked the panels in on it but as you say windows are easy to sort.

I knew a girl who did something like this to a mk3 xr3 years ago, sprayed the windows, headlights, then put glue on the garage door locks so the garage could not be used (the guy had around 5 locks on it as it was in a bad area)

if the owners messed around (which this guy had been) then they deserve all they get