Playing Beyond the Rim our scout thought shooting a hooversled with normal settings on her blaster would be putting bystanders at risk and so she shot it with stun.
I had no idea how to deal with it... I have searched the rulebook to no avail so eventually I gave her the benefit of the doubt only to find that one shot was enough to incapicitate the sled and allowed the party to catch up with the enemy very quickly.
Does anyone know what the official rule for using stun on vehicles is?