First, brainstorm on what you expect or want your carputer to do. Some go for just music while others take it to far higher levels. Really think about what you use while driving and what would just be nice to have.
Also, since the car is new, get VERY familiar with the interior layout and where the hidden areas might be. Peek under the carpet and behind panels to build a gameplan on where to put the equipment and how to run cables. Also check with the dealership on obtaining the service manual (not the owners manual) for the vehicle, this will tell you how to get the interior apart as needed.
Do you have some dimensions for us on that dash area?