If I were to buy an used Lamborghini or other similar fancy cars, how would I do it?

Never bought a car in my life so I'm not even sure how it would work with let's say a $20k car but let's say I'm rich and I want to buy a Lamborghini Aventador SV off autotrader.ca for $800k from someone on the site. Do I just give him $800k in cash or wire him $800k and then register the car as mine or is it much more complicated that that?