I think I would like to have a diesel engine for better mpg. It would sound great and fit well with the persona of the vehicle.
Mount the shifter on the column like my old Suburban had and free up all that space the shifter takes up in the center console.
The socket head cap screws that are all around the interior dash would really look super cool if they were just higher quality bolts. I plan to swap mine out for bolts that are nicely forged. It would cost so little but have a big effect.
Lastly add an optional backup camera because you can not see out the back of this truck.
All and all I am very happy with what GM has done with the H2. I liked it so much I bought one!
Cheers