Hey /o/ does anyone know if it's possible to substitute

I'd expect that you could if they were the exact same part, yeah. But since Germans can't into interchangeable parts, I wouldn't count on it for most things.

>>17736127
uhhh ?????

some platforms are similar. some aren't. the MK4 and b5 are the same for the most part.

>>17736127

For old gens, yes.

However, most current Audi cars don't share many parts with VW. Unless your car is Lambo.

>>17736127
Umm, duh. Didn't /o/ tell you that the S4 is literally a Jetta with leather?

>>17736127
Between the A3 and Golf/Jetta (as well as Beetle/TT) of similar years pretty much every mechanical part is shared, and the B5 Passat, B5 A4 and C5 A6 share almost everything as well.
The Touareg, Q7 and Cayenne also share a platform so should have plenty of interchangeable parts too.
Other than that they probably use the same sensors and other electronics as well as the same basic engines, but every Audi from the A4 up has the engine facing north-south whereas every other VW has it facing east-west, the aforementioned Touareg, B5 Passat and Phaeton (disguised Bentley, steel A8) being the rare exceptions.