I bought my Z4M coupe back in 2011 when I was 21, my first proper sports car and a bit of a present to myself for finishing Uni. I regrettably sold it to go traveling after 3 years and 20k. Then had a couple of Porsches in-between and came back and bought a Z4MR.
They certainly get under your skin. There isnt much with this calibre anywhere near the value for money.
Back when I got mine it was the financial crash and it had 46k on it with a 2 year BMW warranty and I paid £18k for it. Serious serious bargain.
Only negative is the increased in cost for the M, the 3.0SI offers 80% for about 50% the cost to run. They are incredible tho getting a bit more difficult to justify considering the lack of appreciation unlike other M cars in the same class. This year the tax was £695 and my insurance in Manchester was about £600 then I had my exhaust restored with all original bolts, mounts dampeners etc and just a standard oil/brakefluid service and that was £600 so nearly £2k just to have it on the road not including fueling it. Spent £1000 a year on issues and servicing over the 4 years ive had it.
I did find my M coupe a bit claustrophobic but mine was an all black interior, if you have a brighter combo it helps. I also got headaches on long journeys in my coupe for the first 2-3 months even with the standard exhaust I found it droned quite a lot. It's something I did get used to tho, apart from the exhaust the experience in the cabin was a bit non event, the engine up front is really quiet. I work as a photographer and it wasn't until I was in the boot of the follow car while photographing my Z4M driving toward me that that I learned how loud the induction noise was. I had no idea because you don't get much of it in the cabin. Probably because your ears are over the rear axel and you get more exhaust.
BMW Z4M Coupe, Silver Grey, CSL wheels by
Tom Scott, on Flickr
The roadster isnt as good to drive, it doesn't feel as sharp and the quicker rack and stiffness in the coupe are the main contributors but I wouldn't call it night and day they are very similar. The coupe also looks so much better imo but the roadster is a better aural and visual experience. The noise with the roof down of the exhaust and induction is really quite intoxicating so I don't really miss my coupe apart from the way it looked, seriously one of the best designs BMW have ever made. Peoples reactions to it were great too, constant thumbs up, interaction at meets. The roadster does blend in a little more, saying that mine is a 1-4 combo which is quite rare so have enjoyed taking it to meets etc they are all rare and people tend to be pretty interested!
Having been one of the few people to have gone coupe to roady.... I went that way because I had a Boxster really didnt like the car but realised I preferred the top down. It was my first convertible and previously thought they were hair dressers cars (insert usual negative comment on convertibles) then got a Carrera 4S convertible and loved it but it was pretty lardy on the road not much fun to drive quickly but a great cruiser and sounded epic with the sports exhaust, I then bought a Z4MR ran them both through the pandemic then with the prices soaring sold the 911 making a few £ to put into the M.
It is funny as I used to be a bit like MrTidy with my comments like the coupe is the be all and end all and I wouldn't consider anything else, but I hadn't experience the roadster and I was completely wrong and happy to admit that 15 years later. In fact when I had my coupe I went as far to say that I really disliked it and wish I had experienced it a bit earlier.
When you experience the roady the positives of the coupe kind of drift away. Unless you are seriously driving it hard all the time which I don't, its enthusiastically driven and I go to a lot of meets and have a holiday home in the lakes so spends a lot of time on the motorway driving to good roads.
Considering the roadies with similar milage are literally about 2/3rds the cost im surprised people don't see them as even more of a no brainer.
Horses for courses, both have pros and cons and neither are perfect at all. The coupes certainly seem to suit the UK weather but most vert owners seem to be pretty hard core with the roof down at every opportunity.
Lucky to have experienced owning both. The more cars the better
BMW Z4M Roadster, Zedfest 2023 by
Tom Scott, on Flickr
BMW Z4M Coupe rear by
Tom Scott, on Flickr
Glad your enjoying it!
and whilst my Coupe been around the block a few times which copious owners, over 100k on the clock and now into its 16th year plus being probably the cheapest sports/gt car I've ever owned............its really surprised me how with each passing drive or polish I find myself enjoying this car moe and more. Sadly today was my last drive till the spring as she's being SORN and my OCD for detailing together with my fear of the dreaded winter salt will give me a chance to make some more improvements, seat restoration for the interior and a few mechanical things like replacing the disa units, coil packs and plugs as part of my general ongoing non essential improvements. 
(Faster than the above....much faster 
