Yes. Like Time said - £18/week isn't worth changing car for - £50-100/week, different matter. Just jack in the current job and go for one that pays £18/week more, like you so easily can do ;-)
Don't be so bloody daft.
No.
Yes.
Mind you, having seen it on ebay, I thought it was a Brooklands. Get rid of it, and save up for a Brooklands.