Here is what I came out with so far:

A) modern VIN numbers are composed by 19 elements as deescribed below

1. Country where car was built (S for England)

2. The automaker (A for Jaguar)

3. Vehicle type or manufacturing division (J for Jaguar Division)

4 to 7. Features/attributes like 4 doors, sedan, rear drive (AB4B for XE)

8. Engine type (found different codes for 3 different engines)

9. VIN Accuracy check digit, it is calculated (do not know how) and goes from 0 to 9 and use X instead of 10 (found 3 different numbers in 3 different cases)

10. Model year, it comes from a cycle table and for 2016 (the actual XE) is G

11. Assembly plant for the vehicle (for Solihull is A)

12. First of the 6 digits serial construction number. I found only 2 complete VIN and in both case 9 is used

13 to 17 serial construction number.

Now...... Here are the finding:

Marc's car, 2L diesel 180hp automatic

S A J A B 4 B N 7 G A Thanks Marc for the precious info

Demo car 2L petrol 240HP automatic

S A J A B 4 B G 4 G A 9 0 0 4 3 7

Demo car 3L V6 340hp automatic

S A J A B 4 B V 2 G A 9 0 0 3 9 9

So the common characters are:

S A J A B 4 B G A 9

The so far known engine versions for character 8 are:

N. 2L diesel 180hp

G. 2L petrol 240hp

V. 3L petrol 340hp

We need to find the calculation method for character 9 and then try topix for the last serial that are simply sequential.

I know..... Looks a little weird >>>