Electroactive polymers I reckon are the way to achieve it.
"synthetic muscles" could be flexible - possibly enough to "roll" into a tight ball rather than all that floppy material current ones have to move and store.
Once in place, electricaly activate the polymer and bingo how tight would you want it to be ?
Tidy up the loose corners (no pun intended) and it's a winner.
If you can afford a soft top car that does 200mph+ then you can afford the material
"A woman without curves is like a road without bends, you might get to your destination quicker but the ride is boring as hell'