Wax gives your paint depth and a warm gloss, and lays down a sacrificial layer that gives dirt and water less grip. Carnauba sits deeper in the 'wet-look' end of the spectrum; synthetic wax typically lasts longer. Always apply it thinly to clean, decontaminated paint.

Whether you go for paste or liquid wax is largely a matter of preference. Paste gives slightly more control when applying by hand; liquid is easier with a machine. Both deliver excellent results when applied properly and buffed off correctly.