Okay, I am planning to move to Toronto from Texas. I will be living there for at least a year. And I want to take my 1999 RX with me. What do I need to modify on it so I can legally register it there? Metric odometer? Always-on headlights' relay? Also, I can't find any information on how to estimate customs that I will have to pay.

 

This is probably a good place to start.

http://www.riv.ca/english/html/how_to_import.html

 

Thanks! That helps a lot.

 

As long as you are keeping it and not importing as part of immagrating you should not have to pay taxes on it.
It may just need a DRL relay added for the lights and the odometer does not need to be changed as it shows mph and km/h