I don't see any problem with adding the seat heating pads between the MB-tex and the horse hair. My back seat is from a 560 SEL and the seat heating is little more than a glorified electric blanket. To get the MB tex off, you will need to remove the entire front seat - word to the wise: move the seat back to get the front two bolts, then move it all the way forward to get the rear two bolts. Be sure to do this before disconnecting any power.

You will need to make sure you either wire a relay, or that you make a direct connection to the power terminal near the battery. In either case I suggest using #12 or (better) #10 wire with an in-line 20A fuse. Of course, do as the instructions say, but be mindful it won't work to add the seat heating to an existing circuit as they pull a significant amount of current. BTW, a cool thing about using a relay is you can have the power available only when the key is in ACCY or START (circuit 58), which could save considerably on the battery.

I suggest keeping the stock look, which you can do by getting a coin tray from a 500/560. Some even have the fanfare horn switch. Wiring is straightforward, with help from the FSM. If you get the switches and the tray, try also to get the female molded connectors with at least 4" of wire attached. This will make your life much easier.

Casey

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Casey Cooper
"From a long line of Mercedes ownership"

'86 300SDL 250K miles (Gone, but not forgotten); best diesel I have ever driven, too bad about the Achilles heel.

'81 240D 370K miles (Sold to my brother after 9 years and 150K miles of reliable driving!)

[Five other Mercedes in family clipped for less length.]