I know the Minn Kota Fortrex is cable driven and I think the Terrova is electrical. I could be wrong there. Either way, why can't they add Terrova features to the Fortrex like Spotlock and Auto Pilot?

They could.  But it would probably be overly expensive and cumbersome.

I think that would turn into an engineering nightmare. 

I think that would turn into an engineering nightmare. 

 

I agree.  In most cases, it is more feasible, economically, to develop such things from a clean sheet, than to make modifications that will adapt to existing products.

If you wanted to get a second motor MK has a quick release mount which allows you to switch motors depending on how you're fishing that day. The MK 47 mount bolts to the bow and you would buy a second slide plate for the second motor. You can swap a Fortrex for a Terrova and vice versa in under 5 minutes.

^^^What he said......I'll get mine installled one of these days.