Yes. New Mark I cars. A model which only they can make. The price escalation on those has been high enough that we've opted to spend hundreds of millions reconfiguring the line rather than purchase a modernized version of them.
It was not intentional but the result is the same. Single vendor lockin and they hold patents which prevent other companies from building something otherwise we could get a custom unit (same size/shape and with a LIM system) from another manufacturer.
The TTC is not spending hundreds of millions but a truly staggering $1.2 billion for 5km of track and somehow it is going to take them 4 years to do it.