 Jaguar and their Director of Engineering , Jim Randle , felt these racing cars were too far removed from the product available to the general public , especially with the rule changes that mandated the replacement of the Jaguar V12 engine in the forthcoming XJR @-@ 10 and XJR @-@ 11 racing cars . Therefore , a project was initiated to design and build a car capable of winning Le Mans " in house " , just as the Jaguar C @-@ Type and D @-@ Type had done . The groundwork for the project was undertaken by Randle over Christmas 1987 , when he produced a 1 : 4 scale cardboard model of a potential Group B racing car . 
