my quick search says LPG-installed cars run at 5-10 bar. the roadster apparently at 350 bar. by comparison one is on the scale of car tires and the other is like 35x that.
But also LPG is extremely flammable, while air isn't, and air can be safely leaked in emergency.
For reference, tractor trailer tires run about 7 bar and we’ve all see those videos.
Using Brode's equation a rupture can release 52MJ of energy or 12kg of TNT. An high explosive tank shell only has 11MJ of explosive energy.