Gentlemen Do Not Start Your Engines !

I have said this to people before and it takes a Mustang driving off all by its self for it to really sink in.
DO NOT LEAVE YOUR MUSTANG RUNNING , with no one sitting in it or the emergency brake pulled . I have seen it happen more than once ,the car is running with no one in it and it jumps into gear .This is normally an automatic trans thing .First time i saw it was my old 69 Mach 1 .My brother had it running while he was working under the hood revving it up ,and i just told him to make sure the emergency brake was on and i walked away and heard a crash behind me .It had jumped into drive ,bumped him out of the way and crashed into the front porch post .Didn't do much damage ,but broke the front porch post off, Lesson learned !
I got a call from a local shop today to look at a 66 coupe ,the mechanic was working on it while it was running .It jumped into reverse ,the driver door caught the shop door opening and folded it forward .The car continued out of the shop ,with the mechanic chasing it ,and hit a tree dead center in the trunk lid pushing the back end of the car in about a foot and wrinkled the driver quarter, and i believe the driver rear frame rail .After hitting the tree,the car wasn't finished yet ,it jumped into drive and rammed the front of the shop taking out the grill ,radiator support and drivers side fender and most of the parts under the front of the hood where it came to rest with a puff of anti freeze . I estimate about $2000 in sheetmetal and that is not counting under the hood ,radiator and fan and other parts . I think what may have caused this one to jump into gear may be motor mounts or bad shifter bushings . Any who , take my advise and never leave your Mustang running with out some one sitting in it ,or the emergency pulled .You has been warned i will probably do a thread as i repair this 66.

Well it looks like i may not get the rebuild .I under bid his body shop by a thousand, but he likes his body shop for some reason .I can garintee they will not take the care i would have ,and i would have replaced all the damage not just tried to bondo it . Still a chance i may get it ,i sent some pics of my work .

Yeah i wish i had taken my camera with me to take pics of a real Mustang pin ball game .

They usually go in reverse but my 69 went into drive ,but that was because my brother was revving the motor .My old 66 coupe went into reverse but i had pulled the e brake so it only creeped a bit before i shut it off .

The shift selector on a ford trany can easily be shifted by hand .If the bushings in the shifter or the motor mounts or trany mount are shot ,just the motor running can cause it to shift into gear .It is not just a Mustang thing ,other ford cars and trucks have been known to shift into gear with no one in the thing.
I remember as a kid in Santa Rosa Ca., a hippy had a mustang jump into gear .It jumped into a forward gear knocking him into the engine compartment and winding his hair up in the fan belt and the car went quite a distance before it ran into another car and finally came to a stop. Uh ...Hippy got a hair cut ,but not by choice .

Yes a ford trany does have a detent in the valve body but it doesnt lock it in gear .