At the Detroit show, Stadler told Autoblog, "We promised each other we wouldn't disclose what it cost, but it was not something they were willing to sell."
When asked if Audi had traded some trademarks in return for usage of the Q2 and Q4 brand names, Stadler commented, "Something very much like that, yes".
Stadler also told the website that Audi had tried years ago to complete its collection of Q-plus-a-number nameplates, but was rebuffed by Fiat. With the launch of the baby SUV drawing closer on the horizon, Audi recently initiated negotiations and an agreement was struck.
It's widely expected that a Q2-branded small crossover will be launched in the near future, possibly as early as the Geneva motor show, which takes place in March.
In the past it was rumoured that friction between Sergio Marchionne, the boss of Fiat Chrysler, and Ferdinand Piech, the then chairman of Volkswagen, scuppered talks between the two parties about the Q2 and Q4 badges.
In April 2015, after a fierce internal battle inside Volkswagen's boardroom, Piech stepped down from his role as chairman of the Volkswagen Group.
It's not known, at this stage, what trademarks and, potentially, other properties Fiat Chrysler has gained in exchange for the use of the Q2 and Q4 badges.