is the buick park avenue ultra a good car. someone is selling one with 56,000 miles on it that a little old lady cannot drive anymore. garage kept and great price
Buick Park Avenues particularly the second Generation (1997-2005) with the 3800 V6 engine were fairly good, reliable cars for their time. They are older now so more things (plastic, rubber, belts) may need replacing from age; just keep that in mind.
See links here:
(1st link fast forward to 11:28)
https://m.youtube.com/watch?v=GxZUc3DEpPk&feature=youtu.be
https://m.youtube.com/watch?v=rK9Y-a1-6JU&feature=youtu.be
I mean, you didnt list the price but, assuming its good and the frame doesn't have any holes, its a no brainer.
If its in good mechanical shape (have a mechanic check it) and a good price (<3k) then jump on it.