Historical clue formulations

• Part of Lawrence Welk's introduction — 2015-01-04
• Audi model retired in 2005 — 2013-07-20
• Part of the intro to a piece of "Champagne Music" — 2012-04-20
• U.K. highway connecting London and Dover — 2011-09-03
• "A one and ___" — 2011-01-05
• German superhighway connecting the Ruhr with Berlin — 2010-12-03
• Part of Lawrence Welk's intro — 2010-01-31
• Part of Lawrence Welk's intro — 2009-03-19
• Retired Audi supermini — 2008-08-07
• See 64-Across — 2008-06-24
• Part of a Lawrence Welk count — 2007-01-14
• Welk's "… and ___" — 2005-06-05
• "A-one and _____" — 1994-05-17
• Part of a Welk intro — 1994-02-20