I have an Alpine CHM S620 6 disc changer for sale, this cost £130.00 new, will sell for £90.00. It's in excellent condition.
Extract from an independent re-seller:

The CHM model can be used also in normal mini-bus systems. Built to Ignore Shocks and Vibration. Alpine CD Changers have the most stable mechanism in the industry, featuring a horizontally tracking pickup, unlike conven-tional pickups that track at a 45° angle and are affected by vertical vibrations. In addition, Dual Hybrid Dampers further insulate the pickup from vibration.

• Mini-Bus Compatibility
• Regulated 1-Bit DAC
• High-Speed, Anti-Vibration DT Mechanism with Silicone-Oil Dampers
• 0° — 90° Easy Adjustable Mounting

Thanks
Bob