There is not actually any law which states you can´t drive in flop flips but beware there is a loophole!
If you are stopped by the Guardia Civil and he/she decides that the footwear you are wearing may be a danger while driving you may face a heavy fine.
The road traffic acts in Spain give the officers discretion to decide if you are wearing suitable shoes for driving on the premise that a flip flop or sandal without a back strap may get jammed under a pedal and cause an accident.
In many European countries it is actually illegal to drive in flip flops.
