Here are some photos showing the front and rear seat heights of the Model 3. Front seat near raised platform: Front seat closer to pedals: Rear Seat:
Mode 3 front seats are OK (too low for my liking), but boy the back seats are terrible, no thigh support and a strange seating angle. The only sedan I know of with worse back seats in the Tesla Model S. My friends that have a Model S rode in the back of my E-Tron last weekend, and were blown away by how comfortable the back seats were, and also loved the 4 zone climate control, after the ride we went and sat in the back of their S... haha! Its really bad.