Just a general VAG question - both BMW and Mercedes have 4 pot twin turbodiesels in their '23d and '250 CDI vehicles respectively. Audi had a prototype 2.0TTDI (notice the two Ts) in the Audi Clubsport quattro which premiered the 8P facelift, but no production twin turbodiesel ever materialised.
Resultantly the MQB cars' top of the range diesel is underpowered compared with equivalents of Mercedes and BMW and have been for a number of years. Seems strange to me that VAG never tried to compete here.