I read On the Road too long ago to remember all of it, and as I said I eventually lost my copy of the book. It appears that you lost yours too, because the list you give come in fact from Wikipedia. No true Autopuzzler will hold this against you, since this is no literary contest, and you never said your infomations were taken from the book itself anyway. Two points as said.
The book was written in April 1951. I did some research and they tend to prove what I remembered, that the car with the most importance in the novel is a 1949 Hudson.
In 1949, Jack and Neal met in North Carolina and drove a 1949 Hudson to New York, then to New Orleans to visit Burroughs, and finally to California. Ginsberg helped Jack get his first novel published, "The Town & the City" (1950). Jack and Neal traveled to Mexico. The 'paper scroll' version of "On The Road" was written during April 1951 – legend holds that it was done in three weeks time
This is how it felt being inside one (1950's photograph by "tterrace" on shorpy.com).