Let V(t) be the value of the car t years after 2003.
So V(0)= 32900(= Value of car in 2003)
V(1) = 32900 - 2080 (= Value of car in 2004)
V(2) = V(1) - 2080= 32900 - 2080 - 2080
= 32900- (2•2080) (=Value of car in 2005)
V(t) = 32900 - (t •1840) =Value of car in 2003+t
where t=0,1,2,3,….15 (cos when t=16 value would be negative)
and so V(t)=0 if t >=16.
Equation you want to solve is
V(t)=32900-(t•2080)=18340
So, 32900-18340=t•2080, which implies,
14560=t•2080, and thus 14560/2080=7=t.
Thus the year is 2003+7=2010.
Unless your question has other missing information, the answer is 7 years after 2003.