2018 Audi Tt RS Problems

Fuel tank and EVAP canister has failed on my car out of nowhere. Yes available for inspection. The safety of me and others have been comprised as the fuel is no longer going into my car, but rather leaking out the excess drain hole potentially causing a fire or igniting without me knowing. Along with air being introduced into the fuel tank my engine was sputtering as I had no idea what was happening until later. Once air was mixing with the fuel and the car was running it was hard to drive past 45mph without the car struggling and violently shaking and jerking. Therefore possibly being a hazard for other drivers as I was driving on both highway and local roads. Dealer has confirmed the issue and problem then decided to quote me $6000 for the repairs even after stating it was a design flaw from Audi. The dealership has looked at it and just told me it needs to be replaced due to a design flaw, but took no blame or responsibility of their own to even help me. I would say about a month ago I realized my car was acting weird when I tried to put in gas and it wouldn't fill up all the way as if something was clogged or fuel wasn't being allowed into the tank. Then another week after out of nowhere I started to see the fuel spilling through the excess drain hole then someone pointed out that my gas is leaking out the rear. No warning signs to be exact, just the fact that I couldn't fill up and the gas pump kept clicking on me when I tried to fill up gas like I normally would.