The "flying saucer" antenna is from Jensen and Northwoods installed it on my current rig.
It's junk. With the rig parked in the driveway I get more "stations" with a random chunk of wire attached to the coax up on the roof.
If your antenna is the Jack, and also mounted just a few inches above the roof, it will probably work a
little better.
Part of why neither works well is height, antennas work better higher, being close to the roof means the antenna does not work well, period. Doesn't matter who makes it.
The best, and I mean best, is the old Bat-wing, with the Bat-Man add on.
Tests showing this can be found
here