Detroit car makers, facing weaker sales and falling market share, have cheered the 13% fall in the US dollar against the euro this year, which has put pressure on prices of imports from rivals, Reuters reported. The dollar's more modest 2% drop against the Japanese yen has helped counter the cost advantage of up to $3,500 per imported vehicle that Japanese manufacturers have against their US competitors, General Motors chief economist Mustafa Mohatarem told Reuters.