*chuckle* If only. I *wish* my car was invisible to radar, but that ain't happening.
My Bel(tronics) Pro 500 radar/laser detector, mounted just starboard of the rv mirror, has paid for itself many, many times. About equally from ticky-tack revenue-generating motorcycle cops (ticketing at 3mph over) to state line-haunting packs of revenue-generating pursuit cars (ever seen a border patrol green Camaro SS?) looking for the big dogs at 100mph+.
Fortunately, since acquiring my chariot, I'm much less interested in speeding. I set it at about 5mph over and that's that, with rare exception. I am more interested in acceleration, as we should be, but even with those occasional moments, I'm over 40,000 miles and counting with the Michelin OEMs, so haven't completely left the reservation.