I've done 4 applications with guard and gloss on 3 different cars! (The addiction is strong) that being said I way over applied it on each vehicle because I'm a newbie. I'd suggest a 32oz bottle for a single car and I'd think that should last about a whole year for one vehicle assuming it's a regular car and it gets washed regularly with Adams products and you apply smarter not harder. The stuff rocks though, just try it! One time and I was hooked, smells great, shines great, and you can visibly see the protection via water beading. No doubt a must have!