This is a tough one. A hatch or wagon that is quiet, reliable, has at most 70,000 miles, and costs at most $10,000.
What model year was the Subaru you used to own? The 2010 and up Subaru Outback is much quieter than those sold before 2010. It's interior isn't as nice as that in an Audi, though. And I don't know if you can find one with under 70,000 miles for under $10,000.
The closest fit could be a 2008 Volvo V70 or XC70. (The 2001-2007 Volvos are less reliable.) Or possibly the smaller V50, though I'm less sure of their reliability.
If you're open to something completely different, and don't need AWD, the Ford C-MAX might work.