Apologies for the totally-unrelated-to-physics-teaching plug but I thought I’d share this in case any readers (in the US mainly) were considering buying a radar detector.
After being caught by a speed trap recently I starting doing some research. I eventually settled for the Escort Passport 9500ix (which I totally recommend)
Anyway, I found the reviews on www.whatradardetector.com to be really helpful. I checked back today and it seems like more and more reviews are continuously added. The Passport iQ got a bit of a slating.