Like the A-Team, Magnum's choice of wheels wasn't really suited to his profession. A Ferrari 308 GTS is going to stand out anywhere - even in Hawaii where the TV series was set - making it a strange choice for a Private Investigator. The thing is that the 308 GTS was never Magnum's; it was actually the possession of Magnum's benefactor Robin Masters, a rich novelist who never actually appeared in the series.
With Magnum treating Masters' 'Robin's Nest' home and car like it were his own, what impressionable young lad of the '80s wouldn't want to be him? Even if Tom Selleck's character sported a fairly wild haircut and a very questionable moustache he still got the girls, drove a free Ferrari and generally lived the life of adventure and excess with his ex-Vietnam friends Rick and T.C, the latter having a very cool brown, orange and yellow striped Hughes 500D helicopter. We can all dream that there are people out there willing to let us live in their luxury houses, drive their Italian supercars and ferry us around in helicopters, but it actually happened to Magnum, and we all want to be him because of it.