I think the visors can be acquired from the dealer, no? Both my dad's Civic and Jazz visors were from the dealer. The visors should be long enough to cover maybe a 1 inch gap in the window and still be flat enough to be unobstructive, and of course will not just fall of anytime.

Pag nagpapa carwash ka naman, have the windows rolled down first pag pinupunas nila yung top edge ng window and the inside of the visor, and then roll the windows up to dry whatever got wet. That's just about the only quirk we've experienced.