Foreground transparent object getting motion blurred by background.

I have a sun flare (which can be quite large) that is not writing to depth and as such is getting distorted my the motion of items moving “behind” it.

I need a way to render the flare after the motion blur is complete. Unless there is another way I don´t know about.

Has anyone got experience with rendering translucent/transparent items that do not get motion blurred.

By the way, rendering after tone mapping and eye adaptation is fine also.