Model 3 maintenance is exactly cheap, either:
Determine when you should bring your car to service and learn how to perform daily and monthly checks to ensure optimal performance.
www.tesla.com
- Brake Fluid Exchange and Cabin Filter every 2 years ($3-$400)
- Clean and Lubricate calipers annually ($200?)
- A/C Evac and Recharge with desiccant bag replacement every 6 years - 1234yf is extremely expensive. Evac/recharge alone is $5-600 at most places, plus the desiccant bag replacement. You're probably looking at $800-$1k.
So no, I don't think the Model 3 is significantly cheaper to maintain than your GTI if we are talking about scheduled maintenance.