Phil I went to a firm near Manchester called 'Airconco', they can be foud at www.airconditioningcompany.co.uk They use a drop-in replacement called RS-24. This requires no modifications to the DeLorean and is designed to work well at the lower pressures (2.2lb/~1.25Kg) specified in the service bulletins. They do a lot of work with classics and commercial vehicles which run on R12 and were very complementary about the DeLorean layout for measuring the compressor oil etc. Complete unload of my original R12 charge (<300g), pressure test and reload took ~45mins. Cost was £78 inc VAT and a complementary de- odouriser spray. This seems expensive compared to what some others have paid, but they are the local experts who had experience of classics and were the most knowledgable about the alternatives. Why spend money changing the car to accomodate R134a when the drop-in works without trouble? They did comment that all of the replacements RS24, R134a etc use slighly smaller molecules than R12 so would tend to 'find' any leaks in the system more readily. John Chapelhow DOC 19 : 'Boeing' 0737