Serious first car for apprentices up to 15,000€

Hello to each other, After I had a change of location in the training and is now also responsible for the field service, I am now dependent on a car. The company can not put this unfortunately, but I would get a tank card. At my disposal are 15,000 €. Since I have to deal with a very upscale clientele, the car should come as serious as possible and if possible a dt. brand come from. I will then drive so about 18-20k annually, maybe even more. Most of this will be via highway. The car should have : – Lots of place in front (1,95 large and not straight slim built) -100-120 hp -Navi -climate -compact car / station wagon I had already looked and considered the Golf VI Variant 1.4TSI or an Audi A3 1.6. From the price I also noticed the Mazda 3, there would be much younger vehicles. If you had alternatives or maybe direct listings, which I could look at more closely? I thank you once in advance , HiSec