If I donate a vintage car to a museum, there are no proceeds or sale to report on line 4 a through d. Do I consider my value as the gross proceeds?

I am having difficulty entering my donation because TT requires that there be information on line 4 a through d.  The museum where I donated the vintage car will display it and has information on line 5c of the 1098-c.  When I enter the information provided, TT still requires a gross proceeds amount.  How am I suppose to determine gross proceeds when there were none?