I feel like the sound could have been a BIT better, Maybe a little higher pitched, and no whistle.
The Fox uses the LEGNEDARY Jaguar XK-6 engine, a engine that has a very distinctive engine note, and yall got fairly close, but you could get closer.
The “Turbo” like whistle noises you used just wouldn’t be made by the Fox, its a entirely naturally aspirated Inline 6, it has no kind of forced induction.
And the Engine noise its self is QUITE good, it just needs to a little higher pitched, and looped a little better, because as if you are going full tilt at 60mph, it is kind annoying as it the loop of the sound is very poor, and it sounds like the engine is struggling.
Here is a Good example of how the Fox could sound, from a OF era Jaguar 4.2 in one of the XJ sedans.