I've got an '01 E430 and 95% of the time when i shut the car off, the car will continue play music, but all displays will be off and you can't raise/lower the volume. The radio will stay on for like 10 seconds after i pull the key out. Now, i can deal with that, but for the first time yesterday, the radio wouldn't shut off at all, i even tried shuttin and then locking the doors with no result it played for over 3 minutes till i got back in, turned car on and shut it back off. Has anyone had this problem??

ttt

stock radio unit?

not experienced the problem you described. have you considered/tried to
pull the radio fuse for a bit and hoping that this helps clear its throat....
ie reset the way it looks at its role in the MB universe?

yup stock head unit. The craziest thing is that it will do it for a few days, then it won't for a few startups/shutdowns, then start doin it again. Its pretty embarrassing actually, car likes to listen to music while i leave the car.

It is possessed!!!!!!! Call your priest!!!!!

Have you tried what raymond suggested?

Get the Radio Key remover from local MB dealer for like $7.
Unplug everything that connect to the head unit including the fuse for one min. (well, at least most circuit board able to power cycle after one min, like your PC and Cell phone.)

Ive seen this happen on peoples cars when they have somthing plugged into the cigarette lighter, Unplug the item, radio goes off weird.

MB radios have a delayed relay that retains power for about 3 seconds after the key is switched off. When that relay is about to go, it mulfunctions and retains the power for longer periods. The fuse might be ok but the relay feeding that fuse is telling you to replace it. Get your relay checked and replaced.