This is so far reported only in Spanish-language media. Several hours ago, VW shut its Puebla, Mexico assembly line for the Bora (not sold in the US) because of the Iceland volcano. This is VW’s best-selling car and its largest plant (Puebla also makes most A4-based VWs sold in the Americas, including Golf, Jetta and New Beetle).
The shutdown is typical of just-in-time manufacturing systems; break the supply chain, and final assembly runs out of parts within hours or days. Obviously some critical component (probably lightweight and high value, such as electronic control systems) was being shipped from Germany by air.
Transnational interdependencies are bad news for the economic cost of natural disasters, but perhaps good news for geopolitical stability: transnational just-in-time manufacturing decreases the likelihood of war by increasing its cost to all parties.
War then becomes unlikely unless at least one participant has no economic interdependencies. For example, the US could invade Iraq in part because so few in the West had economic interests there.
How do you end conflict in the Middle East? Install dozens of large, domestically owned, export-driven, just-in-time manufacturing plants in Iran, Iraq and Syria. This would appear to deliver more stability than sanctions, bombing or occupation, because vested interests on all sides would then fight to preserve them.