The story that I heard/copied/hammed up from Wikipedia was that:-
The Espace's design was originally conceived in the 1970s by the British designer, Fergus Pollock, who was working for Chrysler UK at their design centre at Whitley,in Coventry. Later Matra, who were affiliated with Simca, the then French subsidiary of Chrysler, were involved in partnership in the design.
The Espace was originally intended to be sold as a Talbot, and to be a replacement for the Matra Rancho leisure activity vehicle. Early prototypes used Simca parts, and hence featured a grille reminiscent of the Simca 1307 (Chrysler Alpine).
In 1978, six years before the Espace went into production, Chrysler UK and Simca were sold to the French company PSA Peugeot Citroën (PSA), and the Espace design was given to Matra. Matra made the product for Renault for the first three generations.
When the espace got to the Mk4 Renault decided to insource this and then gave Matra the "opportunity" to make their radical new product, the Avantime to compensate...the rest is history as the world wasn't ready for that product and soon afterwards Matra stopped car production altogether.
Fortunately a number of hardy renault alpine fans, brought up on handbuilt French car style, radical concepts, build quality and reliability (?) and BBC top gear have done their best to keep the Avantime alive in the British public's minds, and this has resulted in such popularity that the coil packs are now worth as much as a complete car.
Nevertheless at least one Avantime is now preserved in the unofficial French car museum somewhere in South London.....
Sorry its been a long day...