Wanderluster: Gold

I've made a video on how to complete this achievement:
Darkmoon Faire Achievement: [Wanderluster: Gold] Version 1 (Old)
Darkmoon Faire Achievement: [Wanderluster: Gold] Version 2 (New)

This achievement is easy as long as you reach the first banner before the 4th toll (which is hard) and the last banner before the 8th toll rings. To achieve this you need to be really fast at the start by either taking a speed up, as done in Version 2 (better), or doing as I did in Version 1 (get hit twice from the zepp with the buff from button 3 to get 150 increased speed). You'll want to be able to act quickly when starting over the quest to prevent the speed increase from dropping off.

So I made this macro:

/cancelaura Wanderluster
/run AcceptQuest()

What it does is whenever you press it you dismount from the Wanderluster and when you press it while interacting with the quest giver you can press the macro instead of pressing "Accept". Put it on a keybind that isn't 1-4 and you'll be able to press it even when inside the vehicle.

Right there on the top 5 most badly designed parts of wow this one.

Darkmoon races are divided into 4 parts.

! --> Time as a whole is not relevant. <-- !

Watch your tolls in individual parts of the race.
At the end of the race look at your score. My is:

Blue: 3
Green: 2
Red :2
Orange: 3

When you have 12 tolls i bet you are too slow in first and last part.
Try to correct your tolls there. I hope it helps.