i wouldnt trust slip on spacers with rims worth that much unless u have decent wheel nuts..
if its for a street car or you dont require that much grip, stretch some 235/45s on it... heres mine, 18x10 +17s on a gtst n it didnt rub thanks to the stretched tyres (had 265s on it, couldnt even roll a mm)
on a gtr you shouldnt have a prob with rubbing guard with stretch
265s (undrivable)
235s (perfect)