DCA in cars stands for "Dual-Clutch Automatic". It is a type of gearbox that uses two separate clutches for odd and even gears, allowing for faster and smoother gear changes compared to traditional automatic transmissions. The Tata Altroz DCA is an example of a car that uses this type of gearbox. The Altroz DCA also uses a wet clutch technology with active cooling features, machine learning technology, and a self-healing mechanism.