What body and interior parts are interchangeable?

For instance can I put coupe power mirors on my hatch, what about fenders from a coupe, etc ........ You get the idea

How about exhaust systems........ what is the closest direct bolton. For example a Integra 4 door OE rear axle back works perfect on a 92-95 coupe.

How about door panels?

Any experiences are appreciated!

Thanks in advance.