Just a thought, why not run a real antenna, something bigger and hard mounted, it will do a lot more for you than a tiny antenna and a big amp. I used to run a 102" whip and I could hear everything and people thought I was running a big amp, but I wasn't, I was just running a simple, properly tuned radio and a well setup antenna.
Basically anything smaller than 1/4 wave, TRUE physical length is a compromise, and anything shorter than 1/8 wave and a loading coil is a HUGE loss in receive and transmit... then you add a mag mount to the mix and things get a whole lot worse and heck of a lot faster.
I have a friend that has a 2011 Dodge 3500 quad cab with the Cummins
He used to run the lil wil, but a few weeks ago he switched to this
10 Meter Ham CB NMO Low Band Antenna 26 5 30 MHz | eBay
it is hard mounted into the roof, the coax are hidden in the head liner and it looks really clean, when he take the antenna off he has an NMO cap that is painted to match his truck, just screws on and seals right up, no tools needs at all, only cost like $3 or $4
He said it was a major improvement over the lil wil, it hears better and so far locals say it TXs 100x better than before, and it looks clean and professional, not to mention it was CHEAP