Unless You Drive A Bugatti

Mex 200 up the coast to Barra de Navidad ot Melaque

Choose your hotel. Continuing onward to P.V. means night time driving.

Straight up the coast through Puerto Vallarta, to the Las Varas coast route or up to Tepic then straight on to Mazatlan.

I would dearly like anyone to try and beat that route for speed and avoiding big cities, both. Nothing comes near a half-dozen hours of it, even driving 90 mph when there isn't a patrulla federal.

Yes there are curves in the northern coastline of Michoacan. It's sorta neater than playing Guadalajara bumper tag, or fooling with city transitos (traffic cops).

"Say! I want to drive from Seattle to San Diego, the fastest way."

"Oh try my way! You'll love Denver or Provo".

Sheesh...