Create a Document that displays information about cars. First, create a select with an id="make". It will not have any makes in the options until the page finishing loading. When the page is loaded, have at least 5 manufacturer names you like in that list. When the user selects a make, you will take their selection and create a new select element with an id="model". Populate another select box with all the models of that make.
When the user selects a model, you will display all the information you have coded in your models array. You can use multi-dimensional arrays if you want, or you may just have several array defined for each model. Have a button that resets the page back to its start (no select boxes but the first one: makes).