i'd keep the trike as simple as humanly possible (with the exception of the heated seats). this car was never meant to have a stereo, air conditioning, cruise control, etc.
i think when you start trying to make it a modern car with lots of electronics you're asking for trouble and in the 8,000 miles i've had mine i've never had any desire for an intercom as both passengers are enjoying the ride and if you need to say something to each other you can.
as for the immobilizer, if someone wants to steel the car their going to steal it as it would take about 2 min and a flat bed trailer. i always tell people this is why you have insurance.
