Audi Q3 vs Mercedes-Benz GLA250

What's the difference?

Replacing a popular model is fraught with danger. Existing customers will tell you they love it, while focus groups of non-customers will tell you why they hate it and sometimes carmakers get caught trying to appease both groups.

Sometimes they’ll make it too big or change too much in the search for more sales and ultimately end up removing the elements that made it popular in the first place.

Which is why Audi has been extra careful with some subtle evolution for this new-generation Q3 SUV and Sportback. This isn’t just a popular model for Audi Australia, it has been the best-selling model for the German brand for more than five years, so getting it wrong would be a disaster.

Buuuuuuuur, parp, buuuuuuuuuuuur, parp. Anyone who knows anything about cars immediately recognises the sound of a 45-engined A-class derivative. It's the sound you hear in a tunnel as old mate blasts past with a giant carbon-fibre wing atop his hatchback. It's the sound you hear at 3:00am on a summer morning (if your suburb has no speed bumps, of course).

In short, that sound means big power from a 2.0-litre turbocharged engine, a seven-speed transmission, and a bunch of Germans who clearly had a sense of humour in charge of tuning the exhaust note.

Sure, the GLA compact SUV is probably a slightly unexpected source of all that noise. But then, Merc's Ingolstadt rivals stuffed Audi's stupendous five-cylinder engine into a Q3 to make the hugely improbable RSQ3, so why not do the same with their skirts-lifted A-Class?

To be honest, my expectations for this car were low. So do I owe Mercedes a grovelling apology? Or can I still claim the moral high ground after a week of GLA 45 "ownership"?