So let's review this shall we?
Longest road: Approximately 0.7km
Ford Transit - Cost: 135k brand new.
Bugatti Veyron SS - Cost: 4.4m brand new.
Ford Transit - Speed: 37MPH brand new.
Bugatti Veyron SS - Speed: 140MPH brand new.
Ford Transit with full upgrades:
Total cost: 435k
Max speed: 54MPH (at this speed you cover the longest road in not long at all)
So for over 4 million dollars in difference of the purchase price the Veyron only goes approximately 100MPH faster. But if you want your Transit to go 60, then the Veyron should be going at least 40x that so at least 2400MPH as I am balancing on price nothing to do with the actual car in the real world other than roughly how expensive it may be (to account for speed). Looking up the Ford Transit's real life counter part it goes approximately 0-60 in 8.1 seconds which isn't exactly what I'd call speedy. And obviously the cost of ownership of a Ford Transit is vastly different than the Bugatti Veyron SS, so because we don't have insurance premiums, registration costs, regular tuneups, small collision damage, running over a nail, etc just the one time cost of purchasing the car for the most part you hardly ever pay for anything with your car, so it makes sense that it would be nerfed to its price. So let's take the extreme again, if you total your Bugatti Veyron SS, it still only costs 40 something thousand to repair which I'm sorry is insanely cheap but any more then you would complain that repairing a Transit costs at least 20k so increasing those costs is out of the question. Overall the performance of the vehicle is perfectly reasonable for the cost to own and cost to upgrade.
Also because we can't make the map any bigger than it is the longest stretch of road is really not all that long. So by your own calls to realism even a Bugatti shouldn't go faster than 100 ish in that distance. Essentially "realism" in this case would destroy any sort of balancing as would the "realistic" prices to cars. So without having huge differences in prices and performance like there is, there's hardly any point in owning a Veyron over something like a Kia Forte because the Kia Forte can go well above even 60 like you want your van to, so it'd speed around the map in no time comparatively.
So forgive me but I don't understand what you're complaining about. Cars are only meant to get you from point A to point B anyways and because of map size being a limiting factor we can't have realistic speeds for most cars. Simply put... if you want a fast car... pay for it don't expect to get one cheap once I've balanced them all.
