E60 BMW M5 help

[M5Fanatics]

Hello guys, I'm fairly new to this page and my question has been asked many times. How durable are the E60 BMW M5's. I hear lot's of good and bad stories but can't make up my mind. BMW M5's are my favourite car, I run the largest M5 page on Instagram (M5Fanatics) and its time for me to purchase an M5! Im looking on auto trader in Toronto and I see lots of the 06 & 07 models and only 4 08 models. Im planning to drive the M5 semi daily. I don't plan on beating the car up, I like to baby my cars. I usually drive the speed limit in cities and sometimes on the highway I like to poke the gas pedal from time to time. Furthermore, I have several mechanic friends that specialize in different areas. What year should I look for and do I need to purchase extended warranty from third party companies? Thanks for replying!