Just like you are not concerned with what others drive, they are not concerned with what you drive. Most people don't judge others based on stuff. The people who do judge based on stuff tend to be superficial and have their own sets of issues. I like the two following sayings:
-All that glitters is not gold.
-Big buckle, no cow.
I have many friends with loads of money who drive humble cars, just because it isn't important to them. What is important is living within your means without debt and being able to do things you enjoy, such as travel or work somewhere you might be paid less but enjoy the work. Quality, not quantity.