Hi Cathy,
Yes, and no. The good news is that there are a lot of good deals around at the moment, including offers of up to €4,500 trade-in on older cars (so-called 'scrappage'), which should help you make the most of your old Clio.
PCP is in many ways a great idea as if keeps the monthly repayments nice and low and it guarantees the residual value of your car at the end of the process. However, it really only works properly if you intend to trade in for another new car at the end of the agreement. If you want to keep your car for longer you could be better off going for a more old-fashioned HP agreement, or getting a bank or credit union loan.
Oh and, no, the balloon payment can't be changed - it's part of the agreement you sign at the start of the process and is fixed for the term of the finance package.
And you're right by the way; thanks to all the offers around at the moment, including some very tempting interest rates (including a few 0% offers) there are much better deals on new cars than used, if you're looking at the monthly repayments. Of course, with a used car you are ultimately paying less overall and not paying for the first couple of years' depreciation.