There are many people who think that the make of the car means that the engine is made by the same company. When Rolls Royce started to build cars again after WW2 they used a Buick engine for years, in fact until they were sold to BMW. Since then they have been using BMW engines.
Gearboxes in the main now come from ZF and electrics mostly from Bosch.
I am fairly certain that Jaguar will be supplying the engines now being made in Wolverhampton to many car manufacturers over the world.
When Ford bought Jaguar much of the Ford technology was used to great effect. The Ford Duratorq engine as used in the X Type 2.0 litre Diesel is a fine engine, and the Gemini V6 diesel used in the S Type and the Freelander was designed by Ford and Peugeot.
What makes a car is the design, the equipment used, the materials used and the way it is put together by the manufacturer.
It would surprise many people if they knew how many different companies, mostly in Birmingham, Coventry and the Black Country make the bits that go into a car. I was visiting a Drop Forge in the Black Country some years ago - about 17 - while I was still working, and asked what they were making at the time. I was told that they were making push rods for the Hillman Hunter - a car that was discontinued in the mid seventies, but still produced in Brazil.
The last Car Manufacturer to produce everything for the Car they made in the UK was Ford of Dagenham, who started off with Iron Ore, Blast furnaces, a foundry for the engine castings, Rolling mills for sheet steel, and metal mechanics and sheet metal workers to use various presses to make and put the car together.
Iron Ore cam in at one end and a car came out the other. Now it is specialisation.
Peter.