in the driver's side door jamb you'll see a white sticker with the car's details (codes) imprinted on it. The 1st way to tell is to look at the top left corner where the month/year of manufacture is listed. On the 2001 model 5-speeds made BEFORE 08/01 the car will have the T-45. Cars made on or after 08/01 will have the new T-3650 tranny.
The 2nd way to tell is to look at the trim codes printed along the bottom of the white sticker. About half way across the bottom you'll see "axle", then "TR" then another 3 lettered code (forget what it is). Under the "TR" you'll be looking for a letter "K". If there's a "K" beneath this "TR", then it has the T-3650.
*note...do not confuse the "TR" code described above with the "INT TR" code found on the left side of the code line. This is the interior trim code, NOT the tranny code.
Hope this helps.