you could easyly make the 40kg weight from parts of the car ? computers / battery / any solid hardware . place all of these things , in to a perfectly placed box , allowing it to move - by doing this there is no weight penalty win win yes / no ?

Don't the cartoon ones always shift the weight to the outside of the corner, so the car is in mid-air beyond the cliff edge? Where do you get those tyres - I want some.

OK let's assume that shifting this 40kg lump around can produce worthwhile benefits. But what about the reaction forces from jerking this thing (let's say it's a small anvil, keeping with the cartoon theme) from side to side. Is it possible that the reaction forces would upset the car coming into the corner? Swinging through esses would require the anvil to be accellerated laterally pretty quickly and the force required to do this would have to add substantially to the lateral tyre load, at least during the turn-in...
On the subject of driving in cartoon land: the laws of physics can be safely ignored while driving around mountains and cliffs. Or at least until you look down, at which point gravity kicks in.

Your absolutely correct and also the reason for baffling fuel tanks, makes a noticeable difference.

Being right doesn't make one likeable though.

Jeez what's it gonna take? Cash? Coke 'n hookers?

Suddenly, I like you.

What you need is an 'Acme' Anvil-shifter...

You missed your chance there buddy, I take Pepsi with my Bookers.

disney has a bunch of these tire flying around...the very first attempt at cartoon nano-technology...must be tiny claws coming out of the tires, but yes, the whole car is off the clif - sprung mass to be clear.

Which is why I said in an earlier post that the mass-shifting would need to be computer-controlled. (The Mercedes Benz "Carving" is doing it already)

the 40kg weight is fixed , ounce you enter the weght of the driver , the weight moves to balance the car then its fixed , when you change drivers , he puts his weight into the car and the car changes to accept the new weight , it is even possible that a weight sensor is in the seat , so you dont have to anything , just get in and drive ,

Race sanctioning associations are not terribly fond of movable ballast for safety reasons. If the ballast is movable, then by definition it is less rigidly attached than it could be -- and thus more likely to become a missile in an impact. So except for the odd periodic exception, movable ballast systems are generally not allowed.

You would think that among world-class racing engineers, multi-million dollar technical solutions, etc, this would not be an insurmountable issue, but one former DTM driver likes to tell the story of accelerating down pit lane only to hear a loud kabang. The active ballast package had fallen out on the ground.

I'm also reminded of the oversteering chair. Dr Frankenstein made a drivers seat that was flexibly mounted to the body, the pivot point being adjustable. Obviously the seat makes very little objective difference to the car's handling, yet drivers found an enormous difference in subjective handling depending on whether the seat gave the IMPRESSION of understeer or oversteer. Not too sure where I got that one from.

Either way, one side effect of the chair was to move the driver (and the CG) towards the outside of the corner.