Play YouTube playlist automatically

The code under here is to get automatic the most recent video in the iframe. It returns a playlist with the most recent video as the first video.

<iframe play src="http://www.youtube.com/embed/?listType=user_uploads&list=UnboxTherapy"& width="2000" height="1160"></iframe>

Now I want to let the first video play automatically. The code to play a YouTube video automatically:

?autoplay=1&cc_load_policy=1

If you combine the 2 you get this:

<iframe play src="http://www.youtube.com/embed/?listType=user_uploads&list=UnboxTherapy?autoplay=1&cc_load_policy=1& width="2000" height="1160"></iframe>

When you place the code above on your website the video will load and work properly, but the automatic play function doesn't work. It won't play automatic.

Update after 2 years

Now 2 years later after asking this question there is still no answer. I think it is not possible. Maybe in the future...