hi!
you have 3 options.
nbr. 1 is the IPod Integration Kit from lexus europe, part nbr. PZ420-00263-ME, price around 300,-EUR
nbr. 2 is soundlink from vaistech (www.vaistech.com), sells for about 300,-USD, must be self imported from US
nbr.3 is Dice iPod integration kit Dice kit, sells for about 150,-USD, self import.
lexus integration kit and soundlink adapters are working fine, dice users have reported some troubles but latest versions should work fine.
regards
willi
Or you could just get an iPod FM trasmitter thingy, which are now legal in the UK