Updating: I bought a "Head-Up" MPH display from Amazon.com. It works just fine, if a little slow in keeping up with rapid speed changes; good at cruising speeds. For me the problem is that it plugs into the cigar lighter sockets, which are always on, so I have to pull the plug a bit to turn it off for overnight, etc. Problem could be solved by hard-wiring to a switched outlet; BUT, it takes five volts and I think there is no such switched outlet in the car. There is a transformer in the plug on the supplied cord. I have found several such simple inline transformers, 12v to 5v, relatively inexpensive, and an add-a-circuit component that will piggy-back on a switched fuse in the foot well panel. There are even less-expensive inline cigar-lighter receptacles that could connect to the add-a-circuit. Sooner or later I'll make a choice and work up the courage to go behind the dashboard to hide the wires.
I would sell the Escort 9500ix with extra suction cups, etc. for sixty percent of its current base list price: 449.99 x .60 = 269.99
PS: My solution for avoidance of speeding tickets is to not speed.