Difficult, I've returned two cars in the past with many ongoing faults, both were 6-12 months old and I got a full refunds.
The key to success is get the dealership on your side to make your case with the manufacturer.
Don't go down the road if SOGA or legal terms until you have tried all other avenues, you will then need someone who has legal/commercial skills/knowledge, there are many other potential consumer legislations you could look at but all will take time and money!
Most important of all document everything, all faults, calls, communications in detail, plus any costs incurred, loss of profit etc.
Good luck, pm me if you need help.