Unlike team sports like football and basketball, professional car racing is considered as an individual competitive sport that inspires fan loyalty both nationally and globally. It is also unique because male and female drivers compete against each other under the same circumstances, and gender is supposedly not a determining factor, though throughout the history motorsports have mainly been a male dominated field. There are many studies on analyzing the protective performance of the suit made for some specific sports such as cycling, sailing, flying etc., but limited effort has been made to understand female car racers' expectations from their suits and in particular underwear in terms of performance, fit, comfort, and aesthetic. So, the study was conducted to design and develop an undergarment prototype by investigating and exploring the issues that female racing drivers face while wearing a unisex suit and accompanying undergarment. For this purpose, 18 types of single jersey knitted samples were developed and their dimensional and comfort properties were measured in accordance with relevant standards. The results were evaluated using AHP-TOPSIS multi-criteria decision making method, so that a seamless undergarment prototype with varying structures at areas such as torso and bust was proposed for female racing drivers, which can be improved in parallel with FIA regulations for further study.