Have you rename the gp4 files to jaguar ?
2001 = Jaguar
2006 = Midland
From the tex files you only have to rename the cp_midland.tex to cp_jaguar.tex
(but not sure now if there is a midland cockpit file included).
For your next car installations i think this list will help you:
----------------------------------------------------------------
2001 = 2006
Team 1
Ferrari = Renault
Team 2
McLaren = McLaren
Team 3
Williams = Ferrari
Team 4
Benetton = Toyota
Team 5
BAR = Williams
Team 6
Jordan = Honda
Team 7
Arrows = Red Bull
Team 8
Sauber = BMW Sauber
Team 9
Jaguar = Midland
Team 10
Minardi = Torro Rosso
Team 11
Prost = Super Aguri