Yes, no problem going offline. I bought it with credit card payment, no issues, you are added to Steam content and subscribe to it as usual. I like the mod a lot, very TCR like feeling, you understeer a lot if you try to push too soon on corner exit, which is how it should behave. The tracks are also well done, except the AIW on an oval track which was too slow when I tried it. Anyhow I miss their best track of the season, San Luis Potosí. It feels incomplete without it.