Hi Gill
No transfers are included. What we did was book the airport transfer in advance which was around CAN$14 per person (children free) through an online company, which took us right to our hotel (it drops off at several Downtown Toronto hotels). We didn't need the car at all while we were in Toronto, you can walk to most places and the our hotel even had a subway in the basement to get further afield.
When we'd had the 5 nights in Toronto we collected a car from Union Station, Front Street, just a short walk away and had it for 3 days, and drove to Niagara Falls (don't miss the lovely town of Niagara On The Lake, very quaint!). Book the car through Canandian Affair as well, I think their rates were the cheapest when I was shopping around, paid about GBP90 fully inclusive of insurances, taxes, extra drivers and first tank of fuel.
We then dropped the car off at Toronto airport and just walked through to the terminal for our return flight- very easy.
Incidentally, we just paid the deposit at the time of booking, which was GBP300.00 which included the hotel deposit too.
By the way the 'HTH' stands for 'hope that helps' and not my name!
Just shout if I can be of any more help