Plextor 12/10/32A

Does any one know if my Plextor can be flashed with the 16x burner firmware???

No this is not possible !

Plextors, sadly, aren’t like Lite-on drives, especially old models, so its definitely a no-no. The only way you can improve performance is by upgrading your firmware whenever new versions come out, the newest for yours is 1.10.

The list is here.