radio electrical problems in 2004 360M

Anyone ever had any electrical problems causing battery to drain as a result of a problem with the CD/radio in their 360? Apparently thats the reason for my 2004 360's recent demise. It going to take 10 days+ to get radio looked at so i'm recieving car back today (after 9 days) from Greypaul Edinburgh UK 'sans' radio - with the hole taped up - classy. Its a Becker unit, anyone experience similar??. I really hope this isn't the start of a long and exhaustive process where they just start with the radio and move on untill they find what the real cause of the power drain is. I'v done 2,100 miles in 11 months, well above minimum required for warranty to apply. (yes their is a minimum mileage believe it or not!). Can anyone reassure me??