i've done these conversions at my shop for "cost is no object" customers, and if "cost is no object", then it is possible. some have the wiring, some don't. this is not an item MB ever planned to offer as a retrofit and it will cost you multiple thousands of dollars to convert them. i am with gilly, either accept the lack of heated seats or find another vehicle (164s will be out in fall). there is the option of adding aftermarket seat heaters, which is a much less cost prohibitive endeavour, although you lose the clean look of the factory install. i had aftermarket seat heaters installed on my RX7tt for about 600.00 for the two seats, and the install looked clean, just not factory.