It could not have a difference, but if it were to have a difference it would be that saying was may imply the product is no longer made their, or saying that it is made in France could imply you don't have it in your hands. Ex: That car is made in France... I wish I had one. or: This cheese is made in France, and it's delicious. With using was: This old gun was made in France, and is very rare. Or: This cheese was mad in France, and it's delicious. The first example of each have different meanings, but the second one of each shows the ability for them to mean the same thing.
More specifically, we say "This car is made in France" when we talking in general about a type of car, such as the Citroën. Citroëns are made in France.
If we are talking about a specific car, we use 'was'. If I was talking about my car with my neighbor, I might say: "This car was made in France."
It's similar to Dombrefiel's example, "This old gun was made in France, and is very rare." This is something you would say about a particular gun you were pointing to or had in your hands.
The other possibility, as Dombrefiel says, would be that you use 'was' to refer to a type of thing that used to be made in France but no longer is. For instance, you could point to a picture of a Bugatti and say "This car was made in France from 1909 to 1963." In that case, you are making a general statement about a type of car, but using 'was' for the past.
The same general rules apply if you are talking about cheeses.