Compact or hidden FM antennas.

[Stuck]

Has anyone had any experience with either of these types of antennas,
CAR Hidden Antenna Radio AM FM Signal Reception Amplifier AMP Booster 12V | eBay (http://www.ebay.com.au/itm/201140194372?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT)
CAR Auto Electronic Windshield Radio AM FM Hidden Amplified Antenna 12V Aerial | eBay (http://www.ebay.com.au/itm/291285856179?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT) .
I'm looking for an FM antenna for my fibreglass boat and I don't want to drill any more holes in it but a solution for under 5 bucks seems a bit to good to be true.

Thanks,
Anthony.

[Tote]

My BF ute has glass mounted antennas with amplifiers from the factory, they work OK but not as well as an external whip which is presumably why they went back to that design for the later models. They are also more directional than an external whip.

Regards,
Tote