I got a mini--antenna cable adapter, and a 'Y' junction, and hooked the rear window antenna up to my aftermarket headunit. Previously, that was disconnected and only the normal sized fender power antenna was hooked up. And then installed a switch to turn 'off' the front power antenna. And what I've found is that the rear window antenna works so well, that by the time I start losing reception on a station, flipping the switch and raising the power antenna barely makes any improvement. I don't think I've bothered raising it for a couple of years now.
Not what I used but it probably works better:
Amazon.com: Carxtc Diversity Antenna Harness Adapter When Installing a New Radio, Fits Toyota 4Runner that has two antenna connector plugs : Electronics