It takes a lot of practice to be able avoid getting wax into cracks and plastic/rubber. Carnuba based wax will dry and if you let it stay for a day it is a bitch to get off. Syntetic stuff like Zaino and some other do not have white residue and you have no problem.
I recommend to use wax applicator to apply and terry towel to buff it off. You can buy an electric buffer, but they are dangerous. Don't use them unless a professional can supervise you.