I hope you are time aligning for a position, measuring to either your nose or ear somewhere close to where you can ad or take a cm or so.

Once that is done, you are not done, depending on what tracks you use also, they need to be approved tracks for tuning and, you still need to reduce output levels on the left side to place the stage or center it, just TA won't fix everything, you still may have a stage closer to the steering wheel, and then you still need to EQ, cutting on on one side, also. If you don't plan to stay put in one position, you will experience issues if you are very picky, I did mine by ear and even though it's not perfect it's good even during driving and reclining the seat a bit.

Some people find the point or tune with the seat position that won't use while driving.