As far as I know, you can not buy dirt 3 anymore. If it is already in your library then nice, otherwise tough luck. Moreover Dirt 3 is arcade-y when compared to Dirt Rally.
If rally is not your thing, try F1 2012 or F1 2014. I have not played F1 2016 & F1 2017.
If you want arcade-y experience, you can try Grid Autosport or Grid 2.