[TKWPrime]

Thanks to all for your responses. I've also been reading the related threads on this topic.

So far, the electronic throttle lock is close to what I'm looking for but I really want something integrated with the OEM cruise control if possible.

I've rejected the mechanical linkage/cable ideas (with and without magnets) due to safety issues. Quite simply, if you have a serious malfunction in a small car, the only person who could likely be seriously injured is yourself. When you are driving a truck and trailer with a combined weight over 15,000 pounds, the opportunity for vehicular mayhem escalates alarmingly.

I looked into various ideas for interrupting or modifying speed sensing for the cruise control but since this data is used by the ECM for other functions, it screws up more than it fixes.

I am really hoping for a solution in software, aftermarket reprogramming of the ECM/cruise control, rather than hardware.