Ex-Formula 1 driver Gerhard Berger has suggested that Volkswagen would be a good partner for Red Bull.
Rumours abound that the German car manufacturer could compete in grand prix racing, with Red Bull owner Dietrich Mateschitz believed to be pushing hard for VW to join the sport.
Berger, who is close to Mateschitz and formerly owned sister team Toro Rosso, refused to quell any speculation.
He told Sky Sports News: "I would say there is a lot of discussion.
"Mercedes in the last two years has put the game up three steps and Renault just didn't invest. I doubt that they're going to be able to catch up.
"But somebody like Volkswagen, fresh coming in, I think they would and I'm sure that would be a good story for Red Bull."
Meanwhile, Austrian newspaper Kleine Zeitung claims that VW has "more or less finished" an F1 engine ahead of a reported introduction to the grid.