As a guy who is lucky enough to currently have both a Z4MR and Cayman 981 I can see exactly where Dan and NickW are coming from.
When you decide to replace the Z4MR you think you are going for something "better" as a complete package and the reality I have found is that you are going for something that is just "different. The Cayman is much, much more expensive, better insulated against outside noise, razor sharp handling and looks absolutely stunning imo. The sports exhaust makes a wonderful noise but you can't really hear it unless you have the windows open.

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The MR is just a different proposition. Both cars are fast but the MR is defo where the fun is. The whole raw, unruly nature of the car, sat on the back axle with that huge bonnet always puts a smile on my face. It feels aggressive and although I feel the Porsche is the better looking car and the one I would rather be seen in. I think the MR is the one I would rather be in.
Either way, considering the MR didn't sell at what was my walk away price I will keep them both for the foreseeable. Nice to open the garage at the moment.
Keep the MR Dan if you can afford to.
H.