Greetings from the Florida Panhandle
First off, welcome to the Forums. We're glad to have you with us.
As to the Audi Q5 as a tow vehicle for a 16' Airstream, it should work just fine. You need to get your Audi properly outfitted to tow a heavy trailer. You should start researching weight distribution/sway control hitch systems and trailer brake controllers.
SuEllyn & Brian McCabe
WBCCI #3628 -- AIR #14872 -- TAC #FL-7
2015 FC 25' FB (Lucy) with HAHA
2005 Suburban 2500 Quadrasteer (Olivia) & 2011 Silverado 3500 (Fred) with Outfitter Truck Camper (Ethel)