I have just taken the VW ipod lead out and put in a Hardon Kardon ipod controller with a connect2 adaptor and my first impressions are that it is a million times better, there is no delay in changing track and you control it just like an ipod.
And there only £30 on ebay at the moment including the carriage.
The only thing i have noticed is that it doesnt switch the ipod off like the VW one did.
Simon