What is quick detailer?
Quick answer: A quick detailer is a spray used between washes to lift light dust and fingerprints while boosting gloss and slickness. It is safe over waxes and ceramic coatings, adds short-term hydrophobicity, but is not a substitute for a proper wash or long-term protection.
A quick detailer is sprayed onto the car to lubricate dust and light soiling so you can wipe it away without causing scratches, and leaves a shine once buffed off.
They are a little controversial. Plenty of professionals argue they are not a safe way to clean a car without introducing micro-marring. Used properly, though, they earn their place.
A quick detailer is handy when water is not available, or as a show-shine to lift fingerprints and light dust off an already clean car. Keep a bottle and a couple of cloths in the boot for bird mess or spots picked up out and about -- just do not lean on it for protection.
Think of it as a finishing product, not a replacement for a wash. It is a light cleaning and gloss-boosting spray for use between proper washes, designed to lift dust, fingerprints and fresh watermarks while adding a bit of slickness and shine. Most products contain a blend of mild surfactants for lubrication, a silica or polymer additive for slickness, and a solvent base that flashes off quickly. The protection lasts a few washes at most -- you are buying convenience and a temporary boost, not durability.
Quick detailers are safe over a cured ceramic coating, with one caveat: do not use them in the first few days of cure on a freshly coated car. After that, they will not harm the coating, though heavy or repeated use can leave residue that masks how the coating is performing. For more on using a quick detailer specifically on a ceramic-coated car, see can I use quick detailer over a ceramic coating?