interesting piece from brandchannel.com which brings up one of the most prominent issues facing these two going forward...
Substitute Mercedes for Audi and it still makes sense. How will they cope with transitioning clients? consider that the new C class grew to accommodate CLA, meaning mercedes is expecting many existing C shoppers to move into CLA's. Wit the C getting bigger it also becomes a legitimate option for E-class clients, The E-class grew and was packed with many features from an S-class making that a viable option for them. What will that mean for both of them as established clients move down the rungs of the product portfolio?Yet for Audi, there also lurks a stiff caution in its launch of the A3. And ironically, the more successful the car is in the US market, where it will take over from the hatchback-style A3, the more difficult this challenge becomes for Audi. The brand has deliberately upped the portion of its sales from higher-priced, loaded "premium" models such as the A7 and A8 sedans and Q7 SUV over the last couple of years, boosting profitability for the company and its US dealers. A hot A3 could erode that advantage.