CLAs are now in dealers and there may be a few things we can learn for the CLA in advance of the GLA's debut.
First things first the CLA forums have had plenty of chatter about how wide, or how not wide the CLA is. Width on the CLA is 1,777 mm, while the GLA is expected to show up 1,804 mm wide. Thats a delta of 27 mm or 2.7 cm or 1 inch. So i suggest going to see the CLA if you have width concerns.
Secondly and much graver than the first is the CLA seems to have strange panel gaps inside the vehicle. Here are a few pics i pulled from one of the CLA forums:
notice the piece of sheet metal sticking through.... compare the open door picture with an open E-class door, see how the door panel extends to the end of the door on the E-class but on the CLA it stops well short...
Take from this what you want, to be honest panel gaps were the one thing I did not expect from Mercedes....
CLA interior door gap - Mercedes CLA Forum