I had the M4CS covered with Xpel stealth PPF and added Ceramic pro on top. I have yet to wash my car and its been over a year but its not my daily (weekend car). I use Blackfire matte detailer and that's it. IMO any PPF is well worth the investment to prevent paint damage, that should be your first mod with matte paint finish. The ceramic pro coating is amazing, spray detailer and dust just wipes off and no scratches.
https://www.autogeek.net/blackfire-m...ail-spray.html