As usual, there are many obvious question (and some less obvious ones):

- How often do you change the available cars?

- Is there a registration for something? (newsletter apart, can your users save a car for later?)

- who will do the actual modifications? How easy for this person to change what (s)he has to change?

- From where do you perform the modifications?

If you need the website up fast, and don't have much experience with dynamic websites, I would go for a simple static website to begin with and then expand it over time.

Personally, I like to go with dynamic websites most of the time. I have templates to help me get going fast and if I ever need to implement some dynamic functionality I can just extend the existing implementation.

do the simplest solution for you(probably static), then expand it if you want