The 2003 and 2004 seats have a lumbar adjustment on the right side of the driver's seat. There's a hole in the cover for it to fit through. If you get a set of 03'-04 seat covers for your '01, you'll have a hole there. Otherwise they'd work fine I think.

You can find a good deal on them every now and again in the buy and sell forum. I picked up both the front and rear from a member here for $100. They had a spot or two on them, but just pop 'em in the washer and they're as good as new.

And yes, excellent investment. I tossed a soda bottle on the passenger seat last week that wasn't completely closed, and looked over and saw a pool on the seat. Nothing leaked through, and it cleaned up fine. They look pretty good too.