I just thought I'd share my experience, though actually I shouldn't want to repeat it to anyone
I have lovely black leather interior in my 1997 528i SE and decided yesterday to spend some quality time with the Autoglym Leather care. So Radio on and down to work. It took about 3 hours to really tackle the whole of the interior and the end result was amazing. Now the downside to this story guys is (and I'm sure you all know) if you don't switch off the interior lights or run the engine you'll end up as I did with a nice FLAT BATTERY!!
Just thought I'd mention it as a caution to anyone as gullible as I was!!