So now you've got to factor in insurance, petrol, mot and service costs and have savings to cover any repairs.
As I said upthread, A5s are insane.
But I've run a succession of cars that had similar cost and complexity (five to ten year old "executive" saloons) and doing it for about £3000 a year is doable if you're a reasonable age and had the eight to ten grand to pay cash for the first car. Each year you pay out five hundred in tax and insurance and an average of a grand in maintenance, and put £1500 into a savings account to provide a buffer against bigger bills and to have the cash on hand to buy another one when the inevitable happens.
This is a slightly more upmarket version of bangernomics, and you can run things like Audi A4s, VW Passats, the sensible end of BMW 3 or maybe even 5 series, Merc C Class, smaller Lexuses, that sort of thing. Provided you are unsentimental and get rid when they get too old, and don't get carried away and start buying moneypits like old Range Rovers, you can have change out of £300 a month for everything apart from fuel and drive around in a nice, decently sized car which will be almost indistinguishable from when it was new.
You can do a cheaper version of the same thing (lower fuel costs, lower tax and insurance, hopefully lower bills) and drive around in five to ten year old Golfs and derivatives (Leons, Octavias, that sort of thing, not A3s as they are expensive and no better) for maybe £200 a month, again having bought the first one.
The problem is the "having bought the first one". If you have to borrow the initial five (for a decent Octavia) to ten (for a decent 320) and repay that over the life of the car, that's an additional £200 to £400 a month. Suddenly the "oh you can run it for £300" becomes £600. Of course, you could reduce the amount you're saving, but then (a) if your existing car goes bang you've got a loan and no car and (b) whatever happens it means you're going to have to borrow for the next car, and so the costs continue. At £500 a month, you're far better off getting a Polo on a Personal Lease.