Can anyone help with a horror movie title. I watched it in the 1970's and it involved:
A car load of teenagers getting llost and ending up in an obscure town.

Some are arrested and put on trial for an obscure motoring offence and sentenced to rode on a rollercoaster which kills them.

One boy is reprieved if he marries the judges daughter which he does.

All characters (except the teenagers) are really grotesque including the judges son(s) who run the scrapyard for all the cars scrapped for the people killed on the rollercoaster.

It ends where the boy escapes, the whole place blows up but the judge has the boys drivers license and goes and lives with him and his daughter.

Any ideas please?

Could be the repulsive Nothing but Trouble. Except it's from 1991, and there weren't any teens so far as I know.