Honestly, this is the best lot I’ve ever seen to do donuts in. The building is night shifted so you’d have to do this during the day however. It’s totally secluded.
http://maps.google.ca/maps?f=q&source=s_q&hl=en&q=1530+Markham+Rd,+Toronto,+Toronto+Division,+Ontario&sll=49.891235,-97.15369&sspn=28.909861,64.335938&ie=UTF8&cd=1&geocode=FaYtnAIdm-9G-w&split=0&ll=43.790428,-79.237218&spn=0.007884,0.015707&t=h&z=16&iwloc=A
Have fun! Drive safe!