Tata Motors today said vehicle sales declined 4.3% to 23,889 units in April 2005 when compared with the same period last year."There was an increase in undispatched stock of vehicles due to unanticipated difficulties in certification and procurement of somecritical parts," the company said in a statement today.Tata Motors' sales of cars and utility vehicles stood at 12,736 units in April, the statement said.While sales of Indica rose 8% to 7,819 units, sales of Indigo were up 6% to 2,881 units, the release added.