Most parts on new vehicles are not made by the vehicle manufacturer themselves, but by other companies that supply them. The manufacturer puts these parts together and makes a car. If a car company were to go out of business, these suppliers would still be able to provide replacement parts, and other companies would also provide aftermarket versions ot the parts.

Even if a car company was to go bankrupt, that bankruptcy would be a reorganization, not a liquidation. They would still be in business.

Dealers are independent business. If the company were to close (not likely) the dealer could still exist as a private shop. Other shop can also work on your vehicle, so you have nothing to fear there.

Do not let fear of the future of the auto industry keep you from buying the car that suits your needs.