i just got a minicooper, and i have alot of problems with what to do for navigation system. First question is, what kind should i get?

should i get a PDA and then load some GPS stuff on it, or is that a waste?

or should i get a regular navigation system, then i dont know which one. Do you guys suggest any?

and finally

WHERE DO I PUT IT?! where can i put it so that it doesnt block anything?

please get back to me, thank you!