If anyone can shed light,please do...Here we have an X-Cellerator with an X-Cellerator on a XX CR (Lookin' good

Sculpted roof,with a flat section in front of the front window and a bulge on the left side.
Same as a XX CR Kinwald.
Below,on the white/green car (love that car...) we have another so-called X-Cellerator (so I'm told) with a sculpted section on the rear of the roof only,and a sculpted section in front of the front window,with again a side buldge.
And a car that I've never quite managed to work out-the XXL.
I've had one of these bodies and they're nice.
Larger windows than an A8008 and a sculpted roof,but again only the rear of the roof section is sculpted.
What goes on?
And what goes on with the XXL?
Did Losi ever release that car? I found a part number for the decal set...somewhere.
Hmmmm....