No longer obtainable due to server shutdown.
To start an online Time Attack race first go onto ‘Multiplayer’ then click on ‘Time Attack’. From here you can ‘Create Match’ if you’re the host or click ‘Custom Match’ if you want to join. I would suggest finding a boosting partner in the boosting thread Here as there are very few people online.
If you’re the host, start by selecting specific settings that your partner can search for. Once you are both paired you can press to customize the settings and choose your cars.