You will need a war machine !!!
In the other way, Dirt is really fun and provide a good balance between arcade and simulation game, and even if you can't pimp you ride, you can partialy repair it after a big crash and this part of the game is just cool.
Physics are just great, you can lose many parts of your car, and graphics are just amazing, you just need a war machine to play with high settings. Ultra high settings are for high end pc but this next gen game need next gen computer to be really enjoyable.