Board Thread:Game Discussion/@comment-28118599-20160512014956/@comment-4939977-20170818185519

If you unlocked V10 Grand Open beforehand by completing 5 stages of Ride the Storm (where the stage prize was the Gallardo GT3 at 50% discount, with the main prize being the Huracan), you can buy the Viper ACR-X and R8 LMS ultra for use in Accolade Open.

The Ride the Storm event in question can also be a Flashback Event, but I unlocked V10 Grand Open from the original Ride the Storm.