SQ5 - Brake caliper problem

Hi all,

Driving the SQ5 for 6 weeks now, having done 5500 miles.

All going well, except for one first problem, worth mentioning.
(as I am not English speaking, it will be a bit difficult to explain the technical side..)

Since a few days I had an increasing rattle in the front axle, mostly at lower speeds (25 mph) and on small road impurities, like sewer covers and junctures between concrete plates...

the rattle quickly became loud and constant enough to become annoying and worrying.
because the rattle immediately stopped as soon as I pressed the brakes, I started thinking of a loose part of the suspension, what might of course be potentially dangerous.

After a whole day searching at the Audi service point, they could say nothing but guarantee that the suspension is in perfect condition and safe
They 'predict' the problem to be both front brake calipers causing the rattle.
Because of my mileage, they say it is possible that the calipers start showing too much clearance/tolerance on their shafts; this, combined with not enough grease may cause the rattle, which stops each time you apply the brakes (because then they fasten themselves)

Given the unanounced nature of my visit they were unable to look into this further today and need to continue after a new apointment.
Because they guaranteed there is no safety issue, the apointment will be in about two weeks

Anyhow, I already wanted to post this, so that in case some of you might notice this problem as well, it might be the calipers.
(most likely this problem is restricted to the SQ5 as they have specific calipers in the front)

all the best