[aprssig] steering wheel control of ham gear

[jimlux]

someone wrote:
One idea, for those who like poking around things....   There is a well
known "Hack" where you can persuade the steering wheel mounted audio
controls of some models from a well known German car maker, to control
the functions of an iPod.   Perhaps some clever bright spark could
figure out how to use the same, to for example, poke the "Details"
button on a D700/710.

--

You probably want to look at Hack-The-Ibus or similar.  There's a whole 
industry of little adapters out there that look at the serial messages 
flowing back and forth on the BMW I-Bus (some of which are things like 
keypresses on the steeringwheel buttons) and translate them into one 
thing or another. The protocol is quite well documented, there's bunches 
of USB widgets to look at the bus and send messages with a PC (for 
testing and development, or if you have a CarPC), and tons of little Pic 
or Atmel widgets that could be programmed.