Okay, I was able to remove that magnet but only after cutting off the front 2 "tabs" that were molded as part of the frame. Fortunately, the plastic is pretty soft.
Before:
Jag 1.jpg
[attachment=0]Jag 3.jpg
...and after. Even then, a good deal of force and a large flat screwdriver was needed to pop that sucker out of there; strong little bugger. No wonder it impaired the running of this so much! This car now runs much smoother, without a tendency to "break away" and performs much better over-all as well. Thanks! Now to look into those other Scalextric cars...
Mark in Oregon