i refurbish alloy wheels for a living and this was a problem for years!i now use a MIPA german laquer,doesnt mix 2:1 like normal 2k more likae a 5:1.its v,thick but can be thinned further.It is designed for use on alloy bannisters and the like.used it on all polished ally wheels now without problems for 3 or 4 years and its v.clear,normal 2K laquer wont stick to shiny polished surfaces!if you have trouble i can get you a litre for 40 pounds odd from my supplier in watford.