Around the various car boards, the Valentine One (V1) is regarded as the very best. However, if you must have a stealth installation, the K40 is one of your only choices. The consensus on the K40 is that it falses way too much (this is the word from the K40 owners). By the way, the K40 is very expensive - over $1,000 installed (and they pay for the first ticket but that's a cost that is obviously included in the purchase price). The V1 is $400...