swr issues

I have a new stryker sr 655 that Im having high swr issues with. I have checked ground continuity and continuity through the co-ax with my multi-meter not resistence with either. Sometimes the swr is so high the radio goes into protect mode, other times it shows around 3, and sometimes it will start a 3 and then go down to around 1.5. Not sure what else to check to get it down

 

18' Rg59 coax, cant remember who makes it, but its not truck stop brand crap. Running 2 3ft fiberglass firestik antennas mounted on the mirrors

 

That's the route I'm going to go. I did get it down some. I had 2 4ft antennas that I swapped out the 3ft for. That brought it from going into protect mode down to about 3. From there I got it down to 2.1. Its difficult to tune both antennas evenly it seems.
What recommendations for antennas do you have. I think Im going to go with a whip antenna like a Wilson or k40 because I go into areas with a lot of low tree branches and the fiberglass ones don't take the abuse very well, even with springs.

 

That's my plan. Going to pick one up this week with some new coax and see how it tunes.