Please READ my entire thread about this. The Tiguan seats and ours are already the same. You can buy a switch for about $60. BUT wiring it and connecting it to work IS the headache. Remember you have about 9 computers interacting all over this car thru the CAN. THEY ALL talk to each other and in specific ways and sometimes sequences. To get this right requires some hefty and anxious CAN wiring - thank Audi for leaving it out so you can get 0.6 mpg more. Putting it back like a Tiguan is a major job. I estimate more than $2K to put the $600 worth of missing parts and harnesses together.
If you want this $2600 worth while you kiss your electrical warranty way good-bye, I can provide the almost-exact details to do it.
Look, NO ONE wants this more than I do. I've done more research on this than Audi - although I wish they would catch up, so they can make a kit and sanction it - but they won't, cuz the solution (ala VW) is NOT the way they would execute it. But I just cannot imagine anyone wanting to spend the nearly $3K and the warranty killer for this. If anyone thinks they're way smarter than me about this - go for it. When you're screwed, just remember, you heard it here first.