@Sshannon ; Thanks! I think sometimes I get too excited with the new toys, that we forget the obvious...Like the missing ground plane because I was just setting this stuff up in my den, and thought a file cabinet would work well enough... probably not! I will test this out on the minivan when I get the chance, and have also ordered an antenna analyzer this afternoon. Will try to remember post my findings later. Also just received my base antenna (Harvest BC200 460-470Mhz 6.5dBi 200W Tunable GMRS UHF Base Antenna) earlier than expected! Will set that up in a more professional manner.
@WRQC527 ; Yeah... It's all brand new cable and connectors. I did not ohm out every piece, but I did visually inspect all of the solder connections (Being employed in the electrical field, I know it sometimes happens!). Looking over the specs of the Binfu antenna, it is listed as "Bingfu Ham Radio Vehicle Car Mobile Radio Antenna Dual Band VHF UHF 136-174MHz 400-520MHz Magnetic Base PL259 Male Antenna for BTECH ICOM Kenwood Midland Yaesu TYT AnyTone Amateur Radio Two Way Radio" I think I may have been thinking of the specs of my purchased "Base" antenna as opposed to what the specs were for the mobile antenna. I'm inclined to think now it may have been a problem with the lack of ground plane / counterpoise and overall quality of the Surecom SWR meter.
Thanks for your input on the matter, as I'm certainly going to reinspect the cables and connectors.