JBL MS-8 tunes too much bass in driver's seat?

Hey folks,

When I tune the MS-8 from the driver's seat, the resulting curve has way boomy/loud bass from the sub. The passenger seat tunings and others are much more sane.

The car is a Mazda Protege5 hatchback. The sub is in the hatch, on the driver's side (basically directly behind the driver).

Any suggestions on how to work around this?

Running front passives with JBL MS-62C, subwoofer is a Dayton HO 10" with a PRs tuned to about 30hz.

I also found that it's definitely essential to disconnect the tweets for T/A.

I've turned up the system volume, such that the whole thing is louder and such that any resonances resonate louder. I wonder whether the sweeps don't excite any bass reflections for long enough?

I haven't dynamatted the hatch and hatch sides yet--that might be causing extra issues?

The sub box is a triple cone-in-an-almost-cube design, with sub firing towards the rear of the car, and the PR's firing to each side of it. I wonder whether turning the sub to fire into the side of the hatch might help the MS-8 "hear" the sub better?