Designer of the 250 Testa Rossa, Sergio Scaglietti, dies.

Sergio Scaglietti held a hallowed place in the house of Ferrari.

One of Enzo Ferrari’s most trusted contributors, Sergio Scaglietti, has died at the age of 91.

The famed designer and custom car builder died Monday.

The entire house of Ferrari was in mourning following Scaglietti’s death.

In a statement on Ferrari’s Web site, Enzo’s son Piero Ferrari, said Scaglietti had a special place in his heart.

“He was one of my father’s best friends. He was next to me with Marco Piccinini the day my father died and stayed with me the whole night until the funeral. I loved him and he was a very important part of my life.”

Chairman Luca di Montezemolo said Scaglietti left an indelible mark on the automaker.

“Today is a sad day for Ferrari. We lost a friend, a travel companion, a man who had his name forever connected to the Prancing Horse,” di Montezemolo said. “Sergio Scaglietti leaves behind the legacy of an artist who, with his talent, created some of the most beautiful cars of our history. (Those who) had the luck to know him like I did will also remember him as a straightforward and honest man, completely dedicated to his work. We will miss him.”

Ferrari honored Scaglietti by naming its 612 grand touring model in tribute to Scaglietti.