I have it on one car. Cquartz Finest is the brand. Comes in a little bottle with an eye dropper, applied with a sponge.
Usually I don't do it because it's hard to spend that much money on something that size that doesn't get you super, duper high, but it does work. Regardless of all the internet arguing between people that like one brand or another, at the end of the day, it makes getting bugs and road grime off your car without leaving residual damage much, much easier. I was driving around in 100* heat through mountain valleys with bugs splattered on my fascia this summer. Same night, shit sprays right off without much work.
Good if you have clear bra too. Will prolong the life. I did not have it on another car that got wasted by 10 days of bugs on a road trip and the clear bra was basically permanently etched with bug guts everywhere.