This has been my concern here in my own country Nigeria. No auto dealers or automakers has ever accepted any crypto particularly BTC for purchase payments
It depends on how widely Bitcoin is used in Nigeria.
Keep in mind that the dealers may still have to receive local currency to stay legal and correctly pay the taxes. So we need a payment processor.
If the use is "big enough", one of the two scenarios will happen:
1. A local payment processor, that already works with VISA and Mastercard, will offer Bitcoin payments in their portfolio. When that happens, many will be able to easily incorporate Bitcoin payments in their business, including the auto dealers.
2. A local auto dealer will be bold enough to use something like BitPay, even if it's from outside Nigeria, but they can offer Bitcoin payments and the dealer will get legally local currency.