Sorry! Here are some dealer sites:
https://www.schompford.com/used-Denver-2006-BMW-Z4-Base-5UMBT93526LE89504
https://www.selectivecars.net/details/used-2006-bmw-z4-m/73447046
https://www.kunibmw.com/inventory/used-2007-bmw-z4-m-rwd-2d-convertible-5umbt93587ly52970/
https://foreignautoconnect.com/vdp/17566232/Used-2006-BMW-Z4-M-2dr-Roadster-for-sale-in-Bloomington-IN-47401
Also please, how does the ride compare between the 'M' and standard models?
For context, the nearest BMW dealer to me is 100 miles away. The nearest 'M' Z4 is 540 miles away, so first hand information is not readily available.
https://www.schompford.com/used-Denver-2006-BMW-Z4-Base-5UMBT93526LE89504
https://www.selectivecars.net/details/used-2006-bmw-z4-m/73447046
https://www.kunibmw.com/inventory/used-2007-bmw-z4-m-rwd-2d-convertible-5umbt93587ly52970/
https://foreignautoconnect.com/vdp/17566232/Used-2006-BMW-Z4-M-2dr-Roadster-for-sale-in-Bloomington-IN-47401
Also please, how does the ride compare between the 'M' and standard models?
For context, the nearest BMW dealer to me is 100 miles away. The nearest 'M' Z4 is 540 miles away, so first hand information is not readily available.