I've owned three roadsters. I've fixed several convertible tops that would not work. I've never heard of a "trunk lid actuator". I assume you mean the trunk latch switch, the switch that tells the CPL/SSM that the trunk is fully closed. They do fail, but no new parts are available, if this is the issue, your next step is to yank from from a junked car.

I do question just who did the diagnosis, anyone I know that understands the system knows that the only source is a junked car.