Did you mean DTC-169? IF so, these are 6x9" speakers that wouldn't be super easy in an e36 vert. The replacements for rears is a 4" mid 1" tweet in a pod in the rear quaterpanel. Upfront are 5.25" midbass drivers, and this would be no easier a place to use them.
If you want better sound (more BOSS), I would replace your existing speakers (with the same size, but better aftermarket speaker), and add a sub.