thanks
yes there will be a tutorial on how to build things.
the only requirement to be able to build vehicles is that you have built yourself, your character. your character can only be built from items that fit the size criteria. any items of a certain size in any order.
you can put together any objects in any configuration using the available attachments.
a seat is required to drive and an engine or motor of some sort is required to have powered attachments. you can increase the power by adding more engines. other than that you can let your imagination run wild.
there will be missions that will need certain types of vehicles, or more accurately vehicles that can do certain things, carry objects, fly to a certain place etc, but again there is no restriction on the vehicle configuration.