The only thing that would stop a centerfire rifle round in a non guard S600 would be the engine block, major driveline bits, and maybe a couple other odd spots where the frame is particularly thick. "Bulletproof" is a term used metaphorically on these cars! Handgun rounds are likely going through most of the vehicle as well. You might get some deflection or deformation (slight slowing) but odds are the round would still be potentially lethal by the time it found the passenger compartment. Your glass/windshield can be taken out by freeway rocks so not much luck stopping a bullet. These care are designed to take a hit from another vehicle or large solid object....NOT a bullet. Waaaaay different physics involved. If anyone ever gets themselves hurt/killed testing this I nominate for Darwin awards on general principals...

Sorry...

PS hatterasguy..."crown vic cars didn't offer much protection" Neither do the vests unfortunately. 7.62x39 (standard fmj, to say nothing of AP) goes right through.