Meguiars Slide Lock and Triple Duty Detail Brushes are pretty handy for this type of task, particularly when combined with the likes of APC's as mentioned above. R222 Total Auto Wash is a nice choice of APC that softens up muck in small gaps quickly and effectively. A few links here to chew over for ideas...

http://www.polishedbliss.co.uk/acata...rush-wash.html

http://www.polishedbliss.co.uk/acata...sh-polish.html

http://www.polishedbliss.co.uk/acata...wash-wash.html