We just released FreeRiderHD.com to open beta! HTML5, playable on mobile and desktop devices, no lag, improved racing and much more! Check it out.
www.freeriderhd.com
We may bring a lite/demo version here to kongregate as well.
Based on feedback we have just released a new version with the track editor in game. Uploading of tracks is still only available at Kano Games. We will hopefully have another update shortly that will fix a bug for outdated flash players.