Q: Is this the correct process what should I be doing?

PAC Hypersonic Speed
Give the character a power action and move it up to its speed value; it adds 2 to its d6 roll when breaking away and can use (symbol) may move through squares adjacent to opposing characters, but still needs to break away normally, during this move, this character may, as a free action, make one close combat or ranged combat attack with its range value halved for the attack. This character must be in a square where it could legally end its move in order to make the attack.

Errata & Changes Hypersonic Speed
[C]If the target character is defeated by the attack, it is removed from the board immediately and the attacking character can occupy that square.
[C]The Hypersonic Speed character commits to the square from which the attack will be made prior to making the attack.
[C]If carrying one or more characters during the Hypersonic Speed action, the attack must be made from a square in which all carried characters can be legally placed

Okay that is all the rules text I could find.

When I use Hypersonic Speed, for a close combat attack I execute it a specific way. Lets say figure starts at location A, I attack from location B, and want to end up at location C. And yes, location C is less than or equal to Speed units and all squares I move through are clear and not adjacent to plasticity powered characters.

What I do is I leave the figure at Location A, and point out each square leading up to location B (attack square) and place a token there. Then I point out each square leading up to location C (end location) and place a token there.

I let my opponent count and check. I then move the character from location A to location C, leaving the token at location B and roll my attack roll. Q: Is this correct process, What should I be doing?

That's fine, but technically you don't need to declare the end of the movement ahead of time; rather, you're done when you're done.

For example, let's say you think your attack from B will KO the character. So you do your thing, hit the target, but CRAP! you forgot about the Stop click it had... so it's still there. Now, you might change your mind: rather than running over to C, you might want to stay in B and block that character's LOF or something like that. That's all fine.

You don't have to decide your final destination square before completing the attack portion. The results of the attack can absolutely alter where you want to end up afterwards. And technically, you should have your character in the square its making the attack from while doing so.

The "correct" process is:

1) Announce the activation of HSS
2) Complete the pre-attack portion of the movement, stopping in a legal square
3) Make and resolve the attack
4) Resume moving to where you intend to finish.

Exactly! I leave the character (or it's ClixAccessory base, free plug! ) at A, declare my path to B where I make the attack, then complete my movement.

Carried characters are placed back on the map when movement is finished.

For HSS, that means they are not on the map when the attack is made. Which means any effects they have (like PC) are not able to be used during the attack.

See below for more technically correct response.

They're off the map until the move action ends, so they're not available for Enhancement, Empower, PC, TTPC, etc during the HSS action.

They're on the map, but in no particular square, until the move action ends, so they're not available for Enhancement, Empower, PC, TTPC, etc during the HSS action.

Thank you Rules Aficionados!

Yes, that is the more correct way of saying it.