Just to expand on vron's input, the OPC warantee can be taken out UP TO the car's 9th birthday (thus covering it until it is 10 years old as the warrantee runs for 1 year). The mileage must be under 125,000 when it is taken out, but no limit to the mileage done in the year.
However, the card does have to pass an OPC 111 point check that will cost about 130 - 200 depending on which dealer you go to and anything wrong has to be fixed at your expense before the warrantee is taken out.
The most attractive looking alternative I found when doing my research is the maintenance plan from Hartech - they are Porsche specialists near Bolton and charge about (i think) 600 per annum which includes servicing and MOT and all labour, but not parts for servicing and any failures. Like OPC they require it to pass their major service / inspection first. The owner of Hartech, Baz is a big contributor on Pistonheads.
Personally I wouldn't waste money on 3rd party insurance plans - my experience is they're not worth the paper they're written on. They'll wiggle out of everything the can, be obstructive, have claims limits which is unlikely to cover an engine (c£12K), or gearbox (c£8K) and will likely not cover the OPC's hourly charges of c£110/hour + VAT.
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