For the Car -> Cars and Truck -> Trucks, make the following mods to the properties of your Combobox on the report:
ON THE DATA TAB:
Control Source= Classification
Row Source Type= Value List
Row Source= "car";"Cars";"Truck";"Trucks"
Bound Column= 1
ON THE FORMAT TAB:
Column Count= 2
Column Widths= 0";1"
What this does is creates a second column with the values Cars & Trucks. The control is still bound to the first column (Car & Truck) but the first column is hidden b/c it's width is set to 0".
As far as displaying a report with both Cars and trucks, open your report in Design View. Use VIEW menu -> SORTING & GROUPING screen to set a GROUP based on Classification. Turn on the Group Header. This will group all records with a Car classification together and then all records with a Truck classifiaction together. (The report will need to have a record source with both cars and trucks for this work obviously.) If you put the Classification combobox we just modified in the Classification Header section of the report, each group will be labelled Cars or Trucks.
Hope this makes sense!
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