Top speed is just the by product of how the entire car is design and built. They don't build cars to purposely give you the ability to break the speed limits.
Take say a 7 series beemer that can cruise seemlessly in such relaxed manner at 110kmph. To have this they had to build a huge-highly advance smooth engine, so the by product of this is a 250kmph top speed....
Then take say an Ariel Atom that can do 0-100 in like 3 seconds. To have that great acceleration they needed to supercharge a k20 from a honda. The by product of that is a top speed of like 230-240kmph....
and so on and so forth..... see where i'm going here??
Then theres the speed limit issues... lets just says, rules and regulations are there for a reason (we all can find a +ve for it if we wanted to), some agree and some will not, some abide, some don't, get caught, suck it up and pay up la... politics of the issue, well thats an entire different story right?