Can't go wrong with Gtechniq G6 Perfect Glass or Autoglym Fast Glass IMO. For me G6 just edges it over Fast Glass but only just. G6 is my go-to glass cleaner but I have been trying out some products (on another forum) for a company called Obsessive Detail and their Clarity Streak Free Glass Cleaner is excellent too. http://www.obsessivedetail.co.uk/clarity-windows-300mlVery easy to apply and wipe off, I've had great results with it. Bit cheeky but here's a link to a review of it I did elsewhere. http://www.vwroc.com/forums/topic/16505-obsessive-detail-user-review-of-6-products/?p=274130IME any of the 3 glass cleaners above will do the job very well.