Raising Bilingual Kids - Rejecting my language and the beggining of trouble

I am not sure why my kids rejected the Spanish language to start with (I have my theories), but it all started when my boy was about 3. He was an early talker, so on our way to his pre-school, we used to play a game. I will point to a thing on the road like a tree and I will say "Arbol" and he will say "Arbol". It was all great. He was finally learning some words in Spanish, until one day I pointed to the tree again and said "Arbol" and he replied "Tree" and the conversation went something like this:

Me: "Arbol"

Son: "Tree"

Me: "Arbol"

Son: "Tree"

Me: That is not the right word, we are playing the Spanish game you need to say "Arbol"

Son (with a very matter-of-fact tone of voice): Mami, you speak Spanish, my grandma speaks Spanish, my auntie speaks Spanish, I am American and I speak American!!!

I knew I was in trouble right there and then. I needed him to know that we were not the only 3 people in the world who spoke Spanish and that Americans like him could also speak it too!

I put a mental plan into action. From then on we were to:

• Only speak Spanish when we were alone (very difficult to do for me)
• Always put Spanish radio in the car (very easy and it reconnected me with the music I love)
• Enroll the kids in a Spanish school (choosing the right one was a challenge, but finally I found Language Stars)
• Read more Spanish books to the kids
• Change our Spanish Vocabulary car game to a "Veo, Veo" game (I spy)

I have been doing this for about 3 years now, and even though I keep breaking rule #1 and still speak more English than what I should, I have seen some results. They understand almost every command, and although they still reply in English, lately I have started to hear more and more unprompted Spanish sentences coming from them. I also see a big difference when they are with my mother who speaks very little English - when they are with her they speak: your guess is right!!! Spanish!!! Broken, grammatically incorrect, but Spanish nonetheless! I call that success.

Do you have any other tips I should follow?

Disclosure: I will receive discounted tuition from Language Stars as compensation for this post. However all facts and opinions expressed in this post are true and my own. Language Stars have not asked me to write about anything in particular, only my true and honest opinion about my experience with their program.  This post have not been edited by a third person.