There was until recently only one real plug and play small tuned antenna for the car that worked and that was the President Virginia well now a tuneable antenna has come to market and the ability to cover a little wider band width with the adjustment at the top of the antenna. More information about this antenna is written down below.
Like with all small antennas the compromise is the banding of the antenna, this is quoted as 65 channels so not enough maybe to cover the legal 80 channels but am sure with some playing around a decent SWR could be achieved.
The Info File:
Should be in the dealers soon if not already there so something different to have a look at.