car keys are good, i used to do pizza delivery on a night in hull, was often aproached by druggies and similar types,trying to steal pizza/money, they never got far! and usua;lly ended up with car keys dragged across their face or smacked across the head with a Maglite, only time that neither of these approaches worked was on a guy high on drugs armed with a craft knife, nothing would stop him, so i ran to my car and ran him over.