This Is No Reflection On You, But...
I decided to be brave and take the picture anyway - I figured if the flash bouncing back was too strong the worst it could do would be to blast my clothes off and burn my face. In the event, nothing bad happened. The Jaguar is polished aluminium and seems to fire the light off into all directions - it is curved enough never to present a flat surface. I think it would be a nightmare for fingerprints but what a fabulous shape!
If you are confronted with a similar problem in your studio on a smaller scale, think of a light cube from Glanz or Promaster. These act as an overall shield from direct light and in themselves are a smooth white . You can do silverware, gold, or jewellery easily and you never have blown-out highlights.
Now when it comes to cars with metallic paint surfaces, you tend to get a different reflection - more spread-out but more problematical in some ways. It can be difficult to get the smear that you get back to register in the right place. The safest thing if you have a slab side or a flat plane that has metallic paint is to position it at an angle and shoot the main reflection out in another direction. I tried this with the Alvis.