Can you still replace shocks and stuts if your car has coilovers?

Coilovers are a replacement (usually an upgrade) for a car that has a Strut Type setup. Coilovers contain a damper and a spring (Coiled "over" the damper).

That being said you can replace or change the springs or spring rates on your Coilovers. In addition you can replace or change the dampers on some of the more expensive Coilovers.

So to answer you original question, you can not replace shocks and/or struts on a car equipped with Coilovers. Apples and Oranges - they are both fruits but not the same kind.

Hope this helps.