Maybe not in a straight line but around corners it doesn't turn into a solid!It's half full. The idea with baffles is to stop it sloshing about - 25 litres of petrol is 25 kg of weight which shouldn't be moving around IMO.
i should think its just more annoying than anything else?
No baffles in a Clio tank.
The tank is saddle shaped over the exhaust with the fuel pump pick up on one side,
in order to get fuel from the other side of the exhaust to the fuel pick up
the tank is designed to let the fuel move from one side to the other during cornering.