You will probably pay no attention to it as you drive by and even if you do, it doesn't have the appeal of the tourist oriented restaurant inviting you in.
Those who go to Café Rodrigues are usually taken by a regular client or follow the recommendation of a friendly local.
It's well worth it. With an average of 10 eur menus, sometimes even less, you get a taste of the real home made traditional Portuguese food. Don't be shy, be brave to try more daring flavours like octopu