spacers for my nimrods

[Calpin]

After talking with the mechanic i use he reckoned 10mm was enough for the rears on my nimrods, but the guy in the local car part shop reckoned 20mms would fit and look better, so ive ordered the 20mms and bolts. i didnt try to say that 10mms was enough but he convinced me to gets 20s, same price as the 10mms but would look better, anyway the rubbing will be sorted in next few days and im not using my car only for short trips. any thoughts are 20mm ok?