Memo to all professional drivers: when checking out a route it's sometimes worth considering clearance under the vehicle as well as clearance over it, particularly if you've got a president in the back of it when you ground the bastard out.
Can't really blame Obama as he probably expected the driver or Secret Service, someone, to make sure the car they insist on bringing everywhere for him could actually make it out of the embassy once it had passengers etc on board, but it still made Oi larf.