The last of these cars were built in 2000 even though they have the 2001 year. Very few made as they were a very unloved car. The design from 97-01 was derided by many. I will admit it is not exactly stylish. But it is comfortable, reliable (after a few expensive fixes to a vintage luxury car notably the shocks) and is fun to drive. It is safe (I was rearended in a 98 q45 and it was totaled, but I thought it was minor damage right away) and you will win in an accident. The engine and transmission will last forever, but you will replace the injectors and coils in the around 180K for sure. Like all cars, a few little things occur in the 200K plus range, not nothing major.
This car has tremendous power and handling. I did find the navigation system did not have newer roads on it, but it is generally accurate within 100 feet and many times within 10 feet. I have a bad back, and yet I find the seats to be comfortable. There are more features than most newer luxury vehicles. Fun to drive.
My Q45t is absolutely awesome. It's not only a classy car to drive but the road performance and gas mileage are unbelievable for a full size luxury car. We have not had one single problem with it, unlike the problems that we have heard about with the G35. I don't understand why Infiniti changed the body style. The 2001 is so much better looking, in my opinion.