Editing changes in car characteristics after tuning (Test Drive Unlimited)

Good day. maybe someone knows how to change the changes in the characteristics of a car after tuning? I just want to make it so that when tuning the 3rd level from the Jaguar XJ220, the XJ220S is obtained (acceleration 4 for a simple one, for the S-version - 3.3; power: 550/680; weight: 1300 + / 1000 +). I know how to change the original x-ki of the Jaguar, I would like to fix the tuning + increase the price.

ps
I play in 1.66a offline.