Countries in Asia generally Bitcoin in other words crypto/digital currency is not legal, but not illegal, so Bitcoin can still be used using local exchanges, meaning: Bitcoin no one controls it use Bitcoin at your own risk and not using it or using it is not a problem for the state.

If your friend has a certain wallet/exchange for making transactions or a site that can accept Bitcoin, I think your friend can make car buying/selling transactions on their dialer with consumers, This is done according to the agreed price in Bitcoin, in my opinion the government has nothing to do with using Bitcoin or cash.

The point is: both parties must have a crypto wallet/exchange to make their buying/selling transactions easier.