Didn't install one in my T4R, but had them on all 3 of my other SUV's.
I chose one of those mid-loaded magnet antennas and placed it on the roof, near the rear hatch. I bought an extension for the cable and worked it behind the interior panels up to the front where mounted. You can even slice the weather-stripping and run the cable there, re-sealing with some RTV.
I liked this installation in that it did not scrape parking garages and stuff as much as a longer element.
Be sure to get a good SWR meter and tune that baby in. I saw no appreciable loss of transmission distance when dialed in.
Good luck