In that case , best bet is probably one of the specialist Mercedes breakers like Mercman or Rob Parker . ( Rob is a member on here : robparker , and is a nice guy , very helpful . He also has an eBay shop robparkerw123 )
heated seats were a fairly rare option on a w202 ( unless you find something like a c280 breaking , which would generally be better optioned ) but I’d guess the heated seat loom from a W210 woukd also fit , just the wiring might be longer .
I retrofitted electric heated seats to one of my W126s , in upgrading from a cloth to leather interior , it wasn’t so bad since I was taking the full interior from the donor car , but it does involve seats out , carpets out centre console dismantled to run all the wiring in ; also worth getting the switch panel from the donor car so you get the extra switches and with the holes already cut for them .
it is also good if you can do the stripping out from the donor car yourself, that way you can see exactly where the cables are routed , get all the little clips etc and put it all in so that it looks ‘factory’ ; that’s what I did .
