Originally Posted by ages944
I'd base it on his age:
55+ : 760Li
I dunno, I know some older guys who act like they're 20. I'll give you my friend's dad for instance. He's 55 or so I think right now, and he's in better shape than me or my friends and he goes rock climbing with us. If it wasn't for the age lines, he could pass for one of us. Plus he drives a new 911 Turbo Cabriolet which is a gorgeous car.
If you want to base it on something qualitative, base it on your dad's personality. If he's one of those guys that likes to ride around in luxury, go for the boat. On the other hand, if he's still young at heart, take for the M3. Somewhere in between, then recommend the M5. After all, the car is for him. Look at it this way, if it's the M3 or M5, you still win in the end.