Mark Riccioni from speedhunters/scene media/top gear mag has one, spends more time being fixed than it does being driven. I asked him about the costs and he just cry laughed.
There were quite a lot of them for sale when I was looking last, now very few- I wonder if they’re being scrapped as large bills come in. Could be worth decent money in a few years as they vanish.
E61 M5 Touring?