He came down in price to CHF 6,000 to settle, or pay us CHF 1,500 + do about CHF 1,000 of work on a rental/lease car, full of bumps and scratches, which we will give back end of month. The lease company would charge us a CHF 2,000 deductible.
No lawyers fees, no hassle to sell the car etc so we took the deal and are happy to move on.
Thanks for all your comments and suggestions.
PS. While he does the repairs, about a week, he'll let us use the Hyundai saving another CHF 450 if we rented for a week.