Hey folks.
For this achievement, all you need is to have 33 stars TOTAL. You do not need to 3-star the maps that came with with 1960's TV Series Batmobile. I just got 33 stars, and the achievement popped right away. I actually found that the handling was pretty good on this Batmobile, so this should not be too difficult. With all of the additional maps now (1989, Tumbler, and 1960's) you no longer have to 3-star every race, and can also say goodbye to having to do 3-lap races!
I would recommend getting 3-stars in all of the single lap courses first(including the 1989 and Tumbler maps), as those are very do-able. I got 3-stars in all of the following, unless I note otherwise. They are the following:
1-Lap Races:
-1960's Penguin Dockyard (2 Stars)
-Batcave Set (2 Stars)
-Ashes
-Cataclysm (2 Stars)
-Cobblepot's Causeway
-Joker Parade
-Midnight Fury TT (Time Trial)
-Cauldron Speedway TT (Time Trial) 2 Stars)
-Crushonator (Riddler Course)
-Condamned (Riddler Course)
-Mental Blocked (Riddler Course)
Don't forget you can also do some Hybrid Maps as well:
-Seek and Destroy
-Road Rage (2 Stars)
I did not even touch the following:
-Penguin Dockyard: 3-Lap Race
-Batcave Set: 3-Lap Race
-Joker Parade: 3-Lap Race
-Ashes: 3-Lap Race
-Cataclysm: 3-Lap Race
-Cobblepot's Causeway: 3-Lap Race
-City Heat TT
With all of the above, I believe there is the opportunity to earn up to 60 stars, making this achievement much easier than the others.
Hope this helped! Happy Gaming. cn_guide