I wouldn't say that it was wrong to have that sticker on their if you are a christian. To those saying that telling other's of Christ's love is not what christians should be doing, would you not try and tell others of something which has changed and which you believe is real. I became a christian about 2 years ago, I DONT think that a JESUS sticker is going to be the most effective way of telling people about Christ.
The bible says that the fruit of the spirit (I.e. how those who follow christ should act) is with: Love, peace, patience, kindness, self-control, joy etc and that those who are not like you should ONLY be shown LOVE. Those who are not doing this, but who are ramming a belief down somebodies neck may not actually know Jesus because they do not live with him in their heart.
Jesus IS love, and if a sticker does not represent this, given the presupposition that it should, then it should not be worn. But if it sparks discussion and Jesus is talked about, albeit in a loving way then there is no problem.
The issue it seems in this thread is that there are many people who get offended by it, or see it as irrelevant and therefore wish for it to be removed. A true christian is tolerant and not judgemental, loving and not arrogant, and kind, not dismissive.
Love to all of you guys in this discussion 
 
safe