A big (well maybe not too big) difference between the Canadian 320i and 325i sedans are the engines.
The 320i has a 2.2-L, 168 hp engine: 0-100 km/h (0-60 mph) is 8.7 seconds for the manual and 9.8 seconds for the steptronic/auto.
The 325i has a 2.5-L, 184 hp engine: 0-100 km/h is 7.6 seconds for the manual and 8.6 seconds for the steptronic/auto.
I didn't read too carefully but I'm guessing that a lot of the features and packages (sport,premium,etc) between the two are similar, if not the same. So the big thing about these two cars is their performance, with the 325i being a little over a second faster than the 320i in their respective manual and automatic transmission catagories. I'd say that if you are interested in having that extra little bit of push under the hood of your BMW then go for the 325i.
I took all this from
http://www.bmw.ca which is the website for BMW of Canada. Other than that I don't really have much more to tell you. I don't live in Canada so I haven't had a chance to drive anything there.
