Im not sure if the back of my car is lowerd or not?

I didnt even notice anything untill a friend of mine mentioned it. The back wheels seem to sit right into the arch nicely as if it had been lowerd where-as the front arches seem to sit a good 7-9 inchs higher than the wheel. When i bought the car it had a tow bar on it so must have been towing something, could this have made it lower?

When i had my astra before that was the same but i just thought it was how they came out the factory, slightly lower at the back than the front?

Is this how my car should be or not?

Cheers Matt