You will need a 1.5 for all grubscrews, a 2.5mm for wheel screws and motor screws, and a 2mm for all other screws. A 3mm is also handy to help changing shock location, but not essential.

For the cost of them just grab another 2mm and a 3mm it wil be worth it in the long run.

Hope you enjot your sexray experience, they are a great car.