Hey tabinha, where in Long Island do you live? I live on the borderline area between the city and Long Island
As for your Cayenne, I would recommend Collinite if you are looking for only durability and long term protection. Collinite can last around 4-6 months not garaged. Sealants like Klasse SG will also provide a lot of protection. I'm sure others will chime in with their favorites. My knowledge with detailing product is relatively limited, so good luck to you!