I like the idea of custom parts.
and I really like the idea for options for an auto shift knob.
even though there already exists a ball shaped auto knob (with no visiable button)...if i remember it was near 100$
I know with "custom one offs" come a higher price....
but what price will you be thinking about selling these items at?
I very much like the idea of manufacturing adapter plates to allow other already produced accessories. like the mirrors.
perhaps a collar that bolts to the auto shifter shaft then you screw in any manual shifter ontop of that....to activate the shift you press down on the shifter.