You might be going in the right direction though.
Car might need to be lowered. Or the diffuser might need to be higher.
Sifu,
What program are you modling in? The widebody kit would be tricky.
I think the front is easy to do. You front flares remind me of the Messiah kit.
The rear will be harder to do. I think studying the porche 911 rear fenders, supra rear fenders, 350z rear fenders and that one ps I did of a widebody concept a while ago, to do the rear fenders.
Here is the JGTC concept I did years ago.
I always wondered if a version of this bumper might look good on a regular alltrac.