| Sorry it took so long to come back. I have spoken with the guy who made the actual mount. Cost would be around £700.00. The only screen we could fit in the space available was the Siemens VDO 5.8", so I used the VDO MS5400/5500 system. Good navi (I think), but a great screen for bright sunlight unlike some others. The actual screen install is fairly involved. You have to remove some of the plastic ribs from the back of the speedo and cut into the air ducts (I had some little inserts made and taped in place). Airflow was not really disturbed much. When I sadly sold my Mini, I simply took the mount out and bought (for £130.00!!!) a new dash top.
Let me know if anyones really interested - maybe if there are a few of you we could get the price down a bit. Personally I was very pleased with the install. It never ceased to amaze people and best of all didn't mess up the appearance of the dash. | 
