I agree with mon. Instead of saying "my son has special needs," I would be as specific as possible with what you think the needs are that are not being met and with suggestions for what things you think would go towards meeting those needs. For instance, you could say that you have ability and achievemnt testing that says he is quite a bit above grade level and request that he be given end-of-year testing for the next few grades up. Then, have a plan as to what you want them to do. Different materials in the regular classroom? Subject acceleration in x,y,z subjects? Whole grade acceleration? IOW, focus them on your DS's needs and give them solutions so they don't have to think too much.
And, like mon says, it's always helpful to direct the school personnel to your child's emotional reactions to schoolilng and what your DS says to you about what he's feeling about school. Schools, in general, are all about your child's emotional well-being (usually much more than his academic needs) and if you can provide reports that your DS himself is asking for more then you come off less like a pushy parent and more like a parent merely trying to advocate.
