Ford currently run a supply chain from the UK, via South Africa, back into the EU.
The engine enters South Africa tariff free, under the SADC-EU Economic Partnership Agreement.
1. Replace/replicate the EU's agreement with South Africa;
2. Negotiate a trilateral agreement between South Africa, the EU and the UK, allowing for cumulative rules of origin
Less complicated - Tate & Lyle. They currently import quite a lot of raw cane sugar from South Africa into the UK under the terms of the agreement.