Ride up to any instance on your horse and enter (stay on your horse).
When inside right click on the exit and wait for the option popup (don't do anything until the end of your cut scene, (then press hide), as soon as you go into hide choose your option normal or epic.
as you spawn outside you are invisable on your horse and can ride , cool when you want to get somewhere fast in stealth.
not sure if this has been posted but i found out by chance sure others know