Linq group by multiple fields with join

 var cars = from c in db.Cars
            join s in db.CarsSold on c.Id equals s.CarId
            where s.SellingPrice > 10000
            group new { c.Id, c.Model }
            by new { c.Id, c.Model } into g
            orderby g.Key.Model
            select new
            {
                Id = g.Key.Id,
                Model = g.Key.Model
            };