Measure the usable flat metal area rather than the entire doorway or the width of the original plastic trim. The actual mounting surface determines the suitable plate size. From LED Door Sills, our Acura LED scuff plates are here:
https://leddoorsills.com/collections/acura-door-sills. If measurements are needed, photograph the tape measure directly against the threshold. Separate images of the available length and width also help reveal curves and trim edges that written dimensions cannot show.
