You could create separate multi-record section editors for each spec type (e.g. engine size, website link, logo etc.). These tables/records would act as your data sources.

On your "products/cars" section editor, you can create fields as Field Type "list" using the spec tables as data sources.
I'd probably set List Options as "Get options from database (advanced)", select the source table, and use "num" for option values with "title/name" for option labels.

When creating "product/car" records you would simply select values from these list fields.
This way when you modify an existing spec record "title/name" field the Label will be updated for any "product/car" record that has it selected.

Does this sound like the direction you're looking to take? Hope this helps.

Best,
Steve

Would the "Save & Copy Button" plugin suit your needs? It will create a duplicate record, then you can modify the fields that have different specs.

https://www.interactivetools.com/plugins/save-and-copy/

Best,
Steve

For example, let's say my two products are Ferrari cars, albeit with many similar specs except a few exceptions. I don't want to have to manually copy and paste lots of repetitive details from  Ferrari A into Ferrari B (e.g. engine size, website link, logo etc.), so it would be great if I could link the repetitive data fields between multiple products to save on data entry time.