you can pluck a cheap four-piston Brembo front calipers brake upgrade straight from Cadillac’s ATS and CTS-V parts bin.

Combined with an adapter kit that typically costs less than the calipers, you can upgrade to four-piston Brembo front brakes for as little as $500 all-in on some platforms.

A more popular upgrade, though, is to pull parts off the spicier CTS-V, which the aftermarket will help you fit to a much broader range of chassis. They come in two flavors, with the first-generation CTS-V using four-piston Brembos at all four corners, while the second-gen upgraded its fronts to six-piston units. The latter are pricier, but still on the cheap end for six-piston performance calipers—especially if you’re willing to buy off-brand eBay parts.

https://www.thedrive.com/news/want-a-cheap-brembo-brake-upgrade-find-a-crashed-cadillac