An intercom system is essential when instructing. When hopping from student car to student car the only viable alternative is a motorcycle intercom. I hate them - I've tried a couple and the wires always break, the volume control stops working, the microphones fail, etc. But for the moment I don't see a viable alternative.
For the Type65 car, I really want to install an in-dash rally-car style intercom. Since multiple people will be in the pax seat I need a microphone/ear-piece component similar to a motorcycle intercom that can be easily slid into and out of a helmet. PTT controls are OK, but I'd prefer voice-activated mics (again, like found in a motorcycle intercom). What I don't want is thin wires that break easily, or cheap electronics that fail regularly.
So far I've not found something that does not require permanent helmet mounting. If anybody knows of a system more suited to the needs I've outlined, please contact me.