want to know if parts from a sunfire will fit on a buick?
You need to be much more specific…what parts and what years??
If the Buick is a Skyhawk, they should. The Buick Skyhawk, Pontiac Sunfire, and Chevy Cavalier were all the same basic car with different names.
There is probably nothing more than fuses on a Sunfire and Century that interchange. When I say nothing, I mean just plain zero. They are completely different cars.
That depends on what parts you’re talking about. Body and trim, not likely. Mechanical parts, maybe.
If it’s mechanical then go to a website for some parts house. Poke in the info for the part in question and compare the part number given for each vehicle. If the numbers match you should be home free.
The Sunfire came out in 1995 as an all-new model, alongside the redesigned Chevy Cavalier. There is no Buick equivalent. The Cavalier, however, shares almost everything with the Sunfire. The only possibility of interchange between a Sunfire and a Buick are engine and transmission parts, but not many Buicks came equipped with the 2.2L pushrod engine that is very common in the Sunfires. Some Sunfires came with the Quad Four, which saw duty in a number of Buicks, but not very many Sunfires came with the Quad Four. Transmission interchange is also a possibility.
I often use http://www.car-part.com for such interchange purposes. My guess is there won’t be much that is the same.