needing some advice here, i have seen this question on here in the past but cant find it now with search.
I had a blaupunkt headunit installed a number of months ago, its been working fine no problems, but lately when i turn of the ignition and remove the key it remains on and playing for about 10 to 15 seconds, very annoying indeed, previously it would just switch off straight away.

what could have happened and how do i rectify the problem advice needed thanks for reading

ss

 

this gets stranger, seems after i pull the key out and flick the wiper lever to on the stereo goes off, all very strange, the shop that installed it just claimed dumb and never heard of it before which is fair but they werent very helpfull and eventually said they would look at it in a few weeks bet i have to pay too, anyway any got any ideas why i am having this problem any solutions ?