Deal alert for you fine folks, as DiRT Rally is currently available for free right now on the Humble Store, as long as you subscribe to the Humble newsletter.
The game originally released in late 2015, so it's a pretty good deal for such a recent game, and honestly I've always found the DiRT series of games excellent fun. Codemasters are veterans in the racing genre, and this is another solid entry in that linage - with 17 cars and 36 rally stages to race on.
The game features various locations including Monte Carlo, Powys, and Argolis, and supports both single and multplayer. Reception to the game was very positive on release, so it's well worth picking up for free.
All you need to do is subscribe to the Humble Bundle Newsletter to get your free key, but the offer will only run until 10am Pacific on the 1st of September, so get in quick.