there's no need to polish, but applying some wax will definitely
help with the shine and provide your paintwork with some level of
protection against water spots from rain etc..
some pple swear by glare, some pple, like myself, don't quite like
it because it doesn't give a deep glossy shine, its your personal
choice. i tried glare but switched to Meguair's. i'm now using Meg
#21, its a synthetic wax aka sealant.
