Thanks for your replies,the lotus was purchased unseen {I know) however this does give me more rights.Its a1974 car and cost a fair amount .But just to muddy the waters re the gearbox,the advert said it was an alan voights rebuilt 5 speed gearbox (alan voights being renowned for doing lotus 5 speed boxes) this box ,according to receipts I have ,was replaced in 1985 by a fully reconditioned box,from another renowned company ,which was then in 2004 rebuilt again,so the rebuilt voights box is not actually in the car.I have contacted the dealer by e-mail telling him that 5th gear is not working so that the fault is logged.and have contacted citizens advice so it is logged.The dealer is having to pick the car up anyway to sort out some other issues ,we will see..Andrich seems to have reinforced what I am thinking re the six months rule,so many thanks