A flutterbudget is a person who spends money extravagantly and quickly without much consideration or planning. They tend to live beyond their means and struggle with setting and sticking to a budget.
He is called a stingy miserly man.
Spendthrift
The meaning of 'prodigal' is 'wasteful'. It means someone who spends money extravagantly, with no thought of saving for tomorrow.
Those who spend money extravagantly (adverb) and indulge in extravagance (noun) are called extravagant. (noun)
Thrifty person
spendthrift
spendthrift
Splurge
That depends on how the person with the money spends it.
When a government spends more money in a year than it takes it, it is called a deficit. When it spends less than it takes in, it is called a surplus.
I don't think money can spend a person, in a car, in Germany.