Tallg, I intentionally put that driver thing in my reply. I know someone will bring it up. I need that comment from someone. In islam, the one who follows its teaching is Muslim. And those who not follows not a muslim. That is the difference between worldly Logic and Divine. One who do not Offer the obligatory Prayer daily can't be a muslim. The one who do not Fast during Ramadan can't be a muslim. Once you accepted Islam as your religion/way of life, then should follow the teachings in full. There is nothing like quarter muslim, half muslim etc. Its clear either here or there. You can't be on both sides as per your likeness and comfort.
During ramadan keep on eating on day time and claim as muslim...(There are exceptions provided by Almighty to drop fasting with certain valuable reasons) he can do that, but he won't be muslim. Who do not respect and value His teaching will not be a pious muslim.