Thanks for your replies sofar guys, to be honest, I am not a Porsche fan at all, but my son says that for my use i.c. long distance driving and the last 400 km's in the mountains, Porsche might qualify best.
Furthermore, reliable, not too exotic, good performance etc.
And: yes, a coupé is stiffer than a cabrio and should be preferred. But I like open air in France.