These two had a strong place in history and are still talked about even today whether negative or positive. It also depends on the people who want to see it, they may not be in the majority but the car would still spark a lot of interest among people who knew their story.
Nothing ever said that museums have to hold up ethical standards. Just because Bonnie and Clyde were criminals doesn't take away the fact they are still wildly famous and popular today. Museums should showcase fascinating things people want to see. Memorabilia from the Bonnie and Clyde era is perfectly acceptable.
The V8 Ford driven by the infamous crime pair, Bonnie Parker and Clyde Barrow, is currently on display at Whiskey Pete's Resort and Casino in Nevada. The display is tasteful and historically accurate. It is the chance to people to see a part of American history up close and personal.
Although not a fun time in American history, the car that held Bonnie and Clyde during their final moments of life should be on display in some museum somewhere. That iconic vehicle is a part of the Great Depression's crime and criminals that were all over the country during that time. The car is not a thing to be idolized, but as a reminder of how bad things were in the 1930s.
A museum should not display the Bonnie and Clyde car for public view because the car is associated with crime and should not be displayed for enjoyment's sake. The morbid curiosity people have with Bonnie and Clyde should not have financial strings attached to it and the memory of their murder spree as pop culture should not be encouraged.