The solution:
- Create a TQuery that gets a collection of Manufacturers by their IDs.
- Create a Detail band.
- Set the DataSet for the report to the Manufacturer TQuery.
- Create Manufacturer Name QRDBText field on the Detail band associated with the Manufacturer TQuery and Manufacturer Name field.
- Create a TQuery that gets a collection of Products by their Manufacturer's ID which is a parameter to the TQuery.
- Create a Sub Detail band.
- Set the DataSet for the Sub Detail band to the Product TQuery.
- Create Product Name QRDBText field on the Sub Detail band associated with the Product TQuery and Product Name field.
- NEW! Set the Detail band's LinkBand property to the Sub Detail band.
- NEW! Prior to Printing/Previewing/etc. the report, in code set each query's Active property to True.
- NEW! After Printing/Previewing/etc. the report, in code set each query's Active property to False.
The part that really threw me off was the "magic" that occurs wherein you needn't specify the parameters between the data source and the query for Products. It appears that if you specify a parameter required for a query pointing at a dataset then the query will look for a field sharing that name and match them.
I hope this helps someone down the road.