Nissan and Vauxhall dealers tend to performs badly in customer satisfaction surveys and your experience backs this up. It seems ridiculous when you actually want to spend money with them, plus all the extra cashflow they'll get when you return for servicing. Toyota, Lexus and Skoda dealers tend to be among the best and Hyundai (and KIA) are fast catching up, as seems to be very much the case in your area. Hyundai also has some great cars and even better ones coming through, so it's a brand you can stick with for years to come. It seems Vauxhall and Nissan have lost a customer, which is Hyundai's gain.