Hi Well reading the posts about retro fitting folding wing mirrors, has started me again on the search for the answer can you fit heated seats into a W221 S320 using original Mercedes parts,there is a company that will do that for the W220 but will only fit aftermarket heated seats on W221,seems weird.
Availability of separate MB heat pads might have a bearing on which models can be done.
On a few the heaters come as part of the seat covering. All still do'able but expensive and pretty sure MB wouldn't list such a retro-fit[/QUERS arded
I got onto a well regarded retro fitter of many items and their web site said the S up to 2005 they could do a merc part retro fit of heated seats but for the W221 only a aftermarket kit,seemed strange,so got onto them this morning with the vin number and they say they will get back to me,and Alfie has asked for the same thing I feel more confident he will get back when he has had time to sort out parts,still watch this space,it annoys the hell out of me that I did not notice this car did not have heated seats when I bought it,again a strange thing given it has options that cost a lot more than heated seats.I think you are right the cost is going to be about 4 times the cost of having it fitted from new but I have to find out
