Fabergé eggs

The New York TimesにあったFerrariのニューモデルthe F12 Berlinetta についての記事から英語表現を拾います。

　　　　　　　　　　
Oxymoron From Italy: The Civilized Supercar
IF one considers the F12 Berlinetta to be nothing more than Ferrari’s latest coupe, the point of the car has been missed. The supercar’s body is merely the fancy wrapping for the gift that is a supremely powerful 12-cylinder Ferrari engine.
…“Collectors are our worst kind of customer,” Mr. Felisa said. “A Ferrari is not meant to fill your garage.” His message was clear: if owners don’t drive their Ferraris — if they are bought for decorative purposes only, the automotive equivalent of Fabergé eggs — sales will eventually dwindle.
http://www.nytimes.com/2012/12/30/automobiles/autoreviews/oxymoron-from-italy-the-civilized-supercar.html?hpw&_r=0

Fabergé eggsとはImperial Easter egg とも呼ばれ，Peter Carl Fabergéというロシアの宝石職人がロマノフ朝時代に王家のために作成した装飾品を指します。FabergéのWebsiteではThe series of lavish Easter eggs created by Fabergé for the Russian Imperial family, between 1885 and 1916, against an extraordinary historical backdrop, is regarded as the artist-goldsmith’s greatest and most enduring achievement.という説明がありました。
cf. http://www.faberge.com/news/49-imperialeggs.aspx
そして記事ではdecorative purposes onlyとあるように「実用的ではない展示物」の比喩表現としてFabergé eggsが用いられています。
ちなみに見出しのoxymoron（撞着語法）はすでにブログで採り上げられていますので，そちらを参照ください。（Koyamamoto）
cf. http://d.hatena.ne.jp/A30/20101024/1287921305