It's good to see people coming up with solutions that are a bit more inventive than the usual hand-wringing apologists and slaughter/shut the borders merchants.
However, 3 questions arise in my mind.
1) Which country were we turning into a car park?
2) Will it be multi-storey with outrageous prices?
3) How exactly is the formation of an enormous (can I say gi-normous?) car park going to assist matters? Are hordes of Islamic fundamentalists going to be sitting over there, scratching their heads, thinking "We'd better not **** with them, they've just turned an entire country into a car park, they're clearly madder than a red-headed Arab".