It's one of the most difficult and often least satisfying modifications that you can make to a build. I would shutter to think of all the kit bodies that have cut open for this modification that have never and will never be finished, simply because in 1/24 it's
really freaking hard to do well. Some people occasionally manage to do a good job, but more often than not a completed build has huge door panel lines (and/or pooly fitting doors) that are simply impossible to ignore. A lot of people would point out that the Tamiya Enzo- a magnificently engineered kit with openable doors designed into the kit- looks much better with it's doors open because the doors never really close properly. (How many kits have you built with opening engine lids that don't quite fit closed?)
It can be done, but if you ever want to finish this build and present it to your father it would be a much better bet to skip the opening doors. Leave them closed, or cut them open and build them open in a static position. Or you could always leave the windows rolled down.
If you want to 'play' with the doors, a diecast is always an option....
