If you are hunting down the absolute best cars to fill your garage in Forza Horizon 6, the legendary 1998 Nissan R390 GT1 is probably sitting near the very top of your wishlist. This ultra-rare, 90s homologation supercar is an absolute beast on the tarmac, but you won't find it sitting in the Autoshow waiting for you to drop credits on it.
The Nissan R390 GT1 is exclusively obtained as a Barn Find. And if you have already tried driving straight out into the wilderness to find it, you probably noticed the barn won't even trigger. To actually get your hands on this machine, you have to play through the game's campaign to unlock its specific rumor first.
Here is exactly how to unlock, locate, and restore the Nissan R390 GT1 step-by-step.
Step 1: Unlock the Purple Stamp
Before the map even recognizes the barn exists, you have to build up your reputation. The barn rumor is locked behind campaign progression. Specifically, you need to reach Level 6: Adventurer in the Discover Japan campaign branch. This specific tier is represented in your UI by the Purple Stamp.
If you aren't quite there yet, open up your Campaign Menu, head into the Collector's Journal, and take a look at your Discover Japan checklist. You can earn the progression points needed to unlock the stamp by doing a bit of everything:

• Knocking out main story missions
• Completing standard road races and downhill/uphill touge events
• Hunting down and smashing regional mascots
• Purchasing player houses across the map
• Clearing general map activities like Speed Zones, Danger Signs, and Drift Zones

Once you hit Level 6 and grab that Purple Stamp, the radio will kick on with a rumor, and a purple search circle will officially appear on your world map.
Step 2: Locate the Barn in Ohtani
With the rumor active, open your map and look toward the bottom-left. The search area drops right into the southwestern corner of the Ohtani region, right along the border it shares with Shimanoyama.
Finding the actual structure can be tricky if you don't know what to look for, so use this exact route to get there:

1. Find the baseline: Track down the main paved road that connects Ohtani and Shimanoyama.
2. Spot the gate: Drive along this road until you find the gate for the Bridge Underpasses Trailblazer activity.
3. Look for the signs: Do not start the Trailblazer. Instead, look right next to the gate structure. You will see an off-road dirt trail marked clearly by two white signs.
4. Follow the path: Turn onto this hidden trail and follow it all the way up the hill. The trail snakes through dense trees, leading you straight to the hidden barn nestled in the forest.

Drive up to the doors to trigger the classic cutscene, and the car is yours.
Step 3: Wait for Restoration (Or Speed It Up)
Once the cutscene wraps, the team will haul the dusty shell back to your garage. Because the R390 GT1 is a highly complex, ultra-rare mid-engine supercar, the mechanical restoration process takes a chunk of time. You have two options here:

• The Patient Route (Highly Recommended): Just keep playing the game. Go run some races, cruise with friends, or work on other campaign stamps. The garage will passively fix the car in the background over time, and it will eventually unlock for free.
• The Impatient Route: If you absolutely cannot wait to take it down the highway, you can open up the Barn Finds menu in your garage and pay a massive sum of in-game credits to instantly skip the timer.

Unless you are completely swimming in credits, it is highly recommended to just wait it out, let the passive fix do its job, and save your money for upgrades and tuning parts. Once the notification pops that the restoration is complete, you will have a pristine, race-bred Nissan icon sitting in your collection ready to hit the streets.