Trying to make a low poly car for a game

If I have a large flat surface that's full of quads (which are the result of loop cuts on the other side of the model), is there any reason not to dissolve the quads if the model is largely going to be static?

For example the underside of a car, I used loop cuts to create the faces I needed for the top of the car, and as a result the underside is full of quads despite being completely flat, can I just dissolve them so the underside is a big flat n-gon or will I have consequences down the line