The whole daily vs weekend thing.
If you're spending all this money on a vehicle, surely you want to enjoy it and drive it. Not just let it sit in the garage and drive it occasionally only?
That is just me though, I know some people like collecting cars and have them sitting around just looking pretty... For me, a car is more about the enjoyment you get out of driving it. If I just wanted to look at a nice car I could simply look at photos. It is not exciting for me.
The M3 and M5 I feel are great options as they are the right combination of daily driver comfort, yet when you want to hoon it and have fun on a weekend (or during the week, when in the mood) you can do so... Kinda like superman, all plain and normal - you whack it into sport mode, press on the accelerator and it is like he has changed outfits and is ready to take whatever he does (I last watched Superman when I was a kid, so may not be the best analogy. lol)
I think you get the idea though.
The M5 you may be taking a step up in terms of creature comforts compared to the 320d, where the M3 and 320d I think are extremely similar in terms of the comforts they come with.
M3 and 3 series in general are more common and popular and you see more boy racers driving them, compared to a 5 series or M5 as mentioned earlier in this thread.
To me the appeal behind the M3 and M5 is the fact that they are soo versatile. It's not a lambo which is super wide, hard suspension, gull wing doors which make it challenging to park in certain spots, super low which means you cannot easily take use the drive through at KFC etc.
Yet they have some serious performance behind them too. They're more than comfortable enough to drive daily as well.
Imagine going to work one day, and on the way home you feel like having a bit of fun. Although you're in your 320d, while the 135KW is reasonable it can't compare to what an M3 or M5 can put out... Now you're stuck in your slower, more economical car... which is comfortable, but isn't bringing a smile to your face anymore.
If you got rid of the 320d the above situation would be avoided and you can have fun all day everyday, when you feel like it. Never need to worry about missing a moment where your vehicle can bring a smile to your face
I think you might as well remove the m240i from your list. Does not sound as if it is the car for you. If you do not like the way it looks, do not buy it. Especially as a weekend car. All that money on a car which you are not 100% happy with is a waste IMO. I think you may regret it.
Is the M135i the new one which is either xDrive or FWD (F40?)