BMW moved to the head of the timesheets ahead of qualifying for their DTM return at Hockenheim with Bruno Spengler topping the second free practice session.
Audi had dominated Friday's first practice by filling out the top six spots, while the best of the BMWs was found down in 12th place.
In second practice Canadian driver Spengler edged out Audi pilot Edoardo Mortara for P1 by just 0.007 seconds. Two more Audi drivers ended up within a tenth of Spengler; Mattias Ekstrom and Mike Rockenfeller.
First practice pacesetter Filipe Albuquerque was next up, two and a half tenths away from Spengler. Jamie Green was the best Mercedes runner in sixth, ahead of the Audis of Timo Scheider and Miguel Molina.
Christian Vietoris placed his Mercedes in ninth, with American GT convert Joey Hand impressing to be the second best of the BMWs in tenth, just ahead of teammates Dirk Werner and Andy Priaulx.
Gary Paffett was 13th for Mercedes ahead of BMW's Augusto Farfus in 14th. Audi debutant Adrien Tambay was 15th, with Mercedes newcomer Roberto Merhi in 16th. Ralf Schumacher was 17th for Mercedes ahead of defending champion Martin Tomczyk in the last of the BMWs. Mercedes trio Robert Wickens, David Coulthard and Susie Wolff were next up, with Wolff's rival female racer Rahel Frey propping up the timesheets again in 22nd place.
Qualifying takes place at 12:40 BST.