People can purchase dishwasher door panels online on Amazon.com and RepairClinic.com, as of 2015. Door panels can also often be found by contacting the dishwasher manufacturer.
Dishwasher door panels on Amazon.com start at about $60 and go up to over $100. Amazon carries all of the major brands, and shoppers are advised to check the part number against manufacturer's information before ordering.
Dishwasher door panels from RepairClinic.com can be searched by brand and part type. The site carries all major brands, such as Maytag, LG, Frigidaire and Electrolux. Prices range from less than $20 to more than $400, depending on the type of door panel a dishwasher needs.