I don't know what the deal is with the 2001's. However I recently replaced the factory one in my 2003 with a pioneer I purchased from cruthfield. While I was looking I did see that they had a few double din sizes that would fit my 03. Out of preference, I went with one where I had to use an adapter bracket. I did this because I wanted a map pocket over the radio once I got it installed. From what I could see the double din size did not give me any extra benifits. Crutchfield was a pretty good deal all the way around. They include everything you need to install the radio including directions, radio bracket, wire harness, and 24 hour support. I also installed new 3-way speakers all the way around. The new radio and speakers are 100 times better than the factory ones.