Rolling in More Gold!

I found a way to easily get the mining Bonanza.

Start low bidding, hit the auto button and almost immediately hit stop. Do this a couple times. 

If you time it out right, A lot of times you can get great payouts and sometimes the mining Bonanza.

I've also found that if you manually spin the slot , and if you tap the STOP button almost immediately after , you are more likely to get the mining Bonanza as well as winning rows. Do this in rapiddly (only bet 10k at first) Once you get the hang of it, start upping your bets.
Alternate between manual and auto spin for better results. Ive won 14million only betting 50k.
I never bet ore than 100k though