I had a Gilbern Invader Mk11 in the 80’s. They had some very good points in that they were a fibreglass body of very high quality and made reasonably well considering the sheds that they were manufactured in. The one memory that stands out was the poor heating system which my wife complained about on numerous occasions. Interestingly enough the current owner contacted me recently to say that he is nearing a full restoration of the car.