How good would an antenna be inside the trunk of a car? For transmitting and receiving, approx 50 watts? It cant be visible and I have not been able to come up with any great solutions...i know you can get covert antennas but they are extremely expensive and do not fit on this car. Any ideas? Thanks! Ive tried those patch antennas that go on the interior of the glass as well, didnt work worth beans on this car