Index and Match function across multiple rows with repeating names

If you are adding more columns, you need to match the range reference (in red) correctly according to your data for this formula to work correctly...

=IFERROR(INDEX($B$2:$M$45,MATCH($O$2,$A$2:$A$45,0),SMALL(IF($B$1:$M$1=$O4,COLUMN($B$1:$M$1)-COLUMN($B$1)+1),COLUMNS($P4:P4))),"")

where
B2:M45 is the total data range.
A2:A45 is the range containing Day nos.
O2 is the cell where you have input the day lookup value.
B1:M1 is the range containing vehicle types. you need to change it accordingly. Like if your last column is say AA1, the correct range will be B1:AA1
O4 is the cell where the formula has lookup value for the vehicle type.
In COLUMN($B$1:$M$1)-COLUMN($B$1), say if your last column is AA1, this will become COLUMN($B$1:$AA$1)-COLUMN($B$1)
In COLUMNS($P4:P4), P4 is the first cell where you put this formula, So if you have more columns and you want to place this formula in say AD4, this part will become COLUMNS($AD4:AD4).

Change all the ranges according to your actual data, and this formula will work.

Hope this helps.