The most expensive car is the Koenigsegg Regera for 1,701,700 credits.
You can unlock this achievement in the test drive. This can be done right at the beginning of the game after the Street Race HQ has been unlocked.
Navigate to the catalog select the Regera, go to headquarters and start the test drive by pressing X.
For me I couldn´t get 2km in one sitting because there is a timer counting down after a couple of seconds. So I tried it again and chievo unlocked after the first 500 meters.
I can confirm on 30 March 2021. You have to drive the Regera and not the other cars
Posted by duncanwarrior99 On 29 Mar 21 at 17:16
there other cars more costly they dont work seem like it has to be koennigsegg regera for it to unnlock
Posted by CobraTodd On 09 May 21 at 06:19
This is because the description says (main game) and the cars who are more expensive then the Regera, where put in through DLC later and where not part of the base game.
Posted by KGI KlikoNL On 18 Jul at 19:56