Ziebart paint and interior protection

Hello, new to the forum. Just purchased 09 G8. So far so great. Love the car and the little Austie characteristics. Lil change from past cars but change is good. Of course when I purchased the car the ziebart paint and interior protection was offered for 5 years (4 applications $500). This car is a daily driver and looking for additional protection to the paint but not sure about the ziebart thing.
I take care of my cars, wash, wax, etc. as needed, but again does the ziebart add protection to the paint/interior, and worth the $$$$$$? If anyone has an opinion out there I'd appeciate any experience (pos or neg).

Thanks and looking forward to the forum chats.

GB