Original cars should have a pretty good fit, judging by the many I've owned; I don't recall any gap wider than 1/4" on mine in that area.
Note the contours on Bill's (62max) pad vs the aftermarket pad, the aftermarket looks more rounded.
It'd be nice to measure the width of an original pad vs aftermarket.
I've played with aftermarket A-pillar garnish and originals and the aftermarket was actually pretty good.
But the originals have the little tabs that lock into the dash frame, which the aftermarket ones lack.