A3 2.0 TDI 140 Quattro-Oil and Turbo

Guys, bought a 06 A3 2.0 TDI 140 Quattro with now 75,000 miles and after 1 month the turbo blew and the garage weren't taking responsibilty for it (A******ES) so i got it fixed at Audi (for peace of mind) and now after roughly a month i checked the oil today and its bone dry.

Any ideas what this could be? Should i just call Audi?

Also in the last few days i've started to hear the police siren whistling noise AGAIN.

My last petrol Audi had 120,000miles on it and never gave me a bit of bother!! Argh!!:aargh4:

Any help would be fabulous!!