As above think long and hard about a change from the Plus 8 as they really are special cars and make no mistake this is the last hurrah for V8's and we are lucky to be able to indulge ourselves, rent a trad Plus 4 and then a 4/4 for a day if you can and then you will find your answer without the heartache for a few hundred squid.
I started off with a Plus 8 in 2004 and put 24,000 joyful miles on it sold it to fund our son's Masters ticket for boats

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A year later 2009 I bought a brand new model 4/4 Sport and it was a great joy for 26,000mls until someone wrote it off for me down a country lane travelling too fast. It was great fun and a really chuckable lithe car but you were forever changing gear to attain the power output.
A month on and insurance paid out and I couldn't wait to get back in a Plus 8 and that's where I am now, a year ago my good lady suggested I bought a new Morgan so I did all my homework and was a gnats away from sticking a deposit on one and then I went out for a long drive in the Plus 8 and realised that I had exactly what I needed already in my hands and the sound track paid a big part in that decision making.
I don't really want a sublime chassis as I thoroughly enjoy the vintage feel of the car and 124mph and 0-60 in 6.5 Seconds is plenty fast enough in the world I live in

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I had wanted a Plus 8 52 years ago and the love affair is not over (coincidentally as long as I have known my wife), had the CX not have had bad reports on the seats and multiple radiator failures I maybe would have been swayed, who knows it's over now. The only reason I would get a Plus Four now would be because I couldn't maintain my own car.