Hi Slam, putting the dogs aside I would go for the coupe as you already know the car and there’s absolutely no comparison as the two cars are worlds apart. You must already have a hankling for the coupe and have probably driven it so why ask the rest of us, your son I reackon will know if he lets it go he’ll miss it so there’s no real need for anyone else’s opinion. Ask the dogs not the wife or us. Yes I’m biased but did own my Z3 2.8 for 11yrs and yes I did miss it, but the coupe will have to extracted from your system and the only way is to own it. As for what your Z3 may or not be worth is purely subjective and as long as you don’t pay too far over the odds for the coupe you shouldn’t loose much if you decide to let it go sooner rather than later. I love driving the coupe to the point that I’m using much more fuel on a monthly bases than I ever did with the Z3. I’m retired and it’s making a hole in my savings but putting an even bigger smile on my face.

Go for the coupe before someone else gets to it first then let me know if I’m wrong.
RHA,Roy.