Best "invisible" radar detector
Although the use of radar detectors is usually legal in passenger cars, a few states ban them completely, and federal law prohibits their use in trucks exceeding 10,000 pounds. Police can use radar-detector detectors -- or RDDs -- to discover which cars and trucks are using a radar detector. However, the Escort RedLine is invisible to RDDs in tests. It's also a great radar/laser detector, picking up signals just about as quickly as the Escort Passport 9500ix (*Est. $500). Unless you really need an invisible radar detector, reviews still recommend the 9500ix as the best choice for typical drivers, as its GPS chip helps it filter out false alerts and detect red-light and speed cameras -- something the Escort RedLine can't do.