performance tuning, car mechanic simulator 2021, engine upgrade, turbocharger, ECU remapping, aftermarket exhaust, cold air intake, sports air filter, high-performance fuel injector, adjustable suspension, coilovers, sport tires, lightweight wheels, aerodynamic body kit, rear spoiler, front splitter, racing seats, roll cage, weight reduction, dyno test, optimized gear ratios, improved cooling system, enhanced braking system, track-ready setup, high octane fuel, custom paint job, racing stripes, vinyl decals, carbon fiber hood, LED headlights, tinted windows, detailed engine bay, performance gauges, NOS system, drift setup, time attack mode, realistic handling, high-speed stability, cornering precision.