Will a Cadillac DTS fit inside of compact car parking space?

No, a Cadillac DTS will almost certainly *not* fit comfortably in a standard compact car parking space. The DTS is a large, full-size sedan. Compact parking spaces are designed for much smaller vehicles. You might be able to squeeze it in, but it would be very tight, potentially damaging the car or other nearby vehicles, and you'd likely overhang the space.