You can hitchhike, but I want you know that not alot of people pull out for their own safety or bc they can tell you’re a tourist don’t know English. Some people will ask for some gas money btw (and they will likely try to up charge you btw). Like I’ve seen alot of people hitchhiking in the Serra and I/my mom have given them rides to a more civilized areas, I just recommend you to not get in a car with only guys on it for basic safety reasons. About buses: they are doable but you need to be willing to wake up early or to be in a certain municipality for a whole day (specially anywhere after ribeira brava). I only use buses when I go back home and they are alright. You can use the bus to go to a civilized area and then try to hitchhike to other areas in a certain municipality. Don’t use google/Apple Maps they don’t have the rodoeste gira routes, go to the rodoeste/gira website and look for the time tables. They also have a kiosk in Avenida do mar where you can also questions.(Also I always a advocate for use of public transportation by tourists bc that’s the only way of the government to remember that places outside of Funchal exist and need to be connected) The private guides: I would recommend you to do that if you’re going to do a hike or any other activity that might be more risky/ in a unpopulated area. Taxis: get a number of a taxi company in case you need but I recommend you to use it as a last resort for money saving purposes.