Does anyone have any tips on how to attach the tamiya rubber tracks? 3 tanks using the heated flathead screwdriver and 3 fails

Needle and thread. I'm so lazy I have been known to use staples. Then I flatten the staple with needle nose pliers and paint it the color of the track.

The old-fashioned way and hope no one notices.

The new Tamiya tracks can be joined with Tamiya cement. They shouldn't need heat or staples.

The old style Tamiya tracks didn't respond to model cement.

Gaz

If they were the glueable type once heat had been applied and failed, you'd have to glue them to the road wheels or thread and staples.

Since he's talking about applying heat, I was pretty sure he's talking about the old style. So it's thread or staples. By the way, read the directions on the glueable style and they say that if gluing doesn't work; use thread or staples.

So anyway you cut it, it comes back to thread and staples.

Thick CA will also work for the old style-- works better if the plugs and holes are still in place though-- if you've already melted them, it may not work as well.
VR, Russ

This applies to the vinyl tracks featured on Tamiya kits designed before 1997. After that year, the tracks used a vinyl-styrene blend that can be glued with solvent type cements. The older kits have continued to be issued with original, vinyl-type track, as far as I know, but you can check by applying a drop of cement to the track sprue, and seeing if it softens or not.
Regarding your problem, you may be applying the screwdriver for more time than you need. Just apply the hot tool long enough to soften the tip of the vinyl stem, then use your fingertip to flatten it out into a vinyl rivet. It should have slight mushroom shape, rather than being completely flat. Position the join on the top run of the track, where it won't be visible. Works for me every time.

Instead of a screwdriver I use the head of a small finishing nail to heat and flatten the stubs. I'd second Gerald, you may be applying heat more than what's needed as I've had that experience before as well.