I was scheduled for a tire change from winter to summer tires, (which are stored at the facility and on rims) as well as an oil change and the standard tune up that is part of the regular maintenance package. My appointment was scheduled for 12:30 PM and I arrived early at 12:00. I was informed it would take up to 2 1/2 hrs due to the balancing required. The vehilde was not ready until almost 4:00 and I also incurred costs for new air / pollen filters. I was informed upon payment that my tires were showing wear and I should consider replacing them. I was also told that I would need brake work on the front brakes and given a price for that work. I left the dealership, completed a quick shop in town and proceeded to drive home on Hwy. 17. Upon reaching highway speeds @ 80 - 100 kms the car / steering wheel began to shake violently and almost uncontrollably. I was forced to lower my speed to under 80 km to continue the 2 1/2 hr trip home. I imediately called the dealership the next day, Saturday and informed them I would be returning to have the vehicle reinspected as I was travelling to southern Ontario that day. After another slow drive back to Sudbury on Monday morning my car was inspected by the dealership mechanics and I was brought in to the garage to be shown that my tires were too far gone and could not be balanced. I was informed at that time that I would need new tires. My disappointment comes from the fact that I spent another 2/12 hrs at the dealership on Monday, a total of 6 1/2 hrs total over two days and that I left on Friday with what I was later told were unsafe tires. I feel the dealership needs to take some responsibility for this lack of safety concerns for its customers. I feel they are currently overbooking and not giving the proper care and dilligance to their customers. I am very disappointed with the service provided in this case.