They were installed as of Feb.'07. Pull the main center duct and confirm. If it is present, it was retrofitted and would be noted on the service history.
Does anyone know when Lotus started actually putting these retrofits into the Elises? I have an 05 Elise and just took it into the dealer to get the retrofit done since I have the same issue with the A/C not working after about 20 - 30 minutes and I'm tired of dealing with the heat. The dealer called and indicated that I have the updated thermostat (part number A120P0149S) in my car. I'm wonder how that is since the retrofit document indicates that this part is assocated with Feb 07 builds.