When it comes to protective vehicles there is reportedly nothing more enduring then President Obama's wheels.
The most recent vehicle to be customised as the presidential car is a Chevrolet Kodiak-based, Cadillac-badged limousine often referred to as Cadillac One. (A reference to the presidential aircraft - Air Force One)
It's armour plating is said to be 8+ inches thick with it's doors weighing as much as those on a Boeing 757. The windows are a staggering 5 inches think, enough to repel some seriously heavy gunfire. The tyres are Kevlar reinforced run flats. Pop the boot and you will find firefighting equipment, oxygen tanks and even a cache of the Presidents bloody type - for transfusions on the run.
When you're as influential and powerful as the President of the United States, a vehicle this excessive is justified.