is there any case for Intelligent design in man made products

That is not an argument.What you would know is that humans had assembled it. You are free to make whatever suppositions about them being intelligent you want but it does not prove it irrefutably.Unless you mean you know it in the same way that people just know God is with them.

these are all valuable things to look at but none of them are a measurement of intelligence.records, notes, etc will show you the process that created the design.Equally you can look at the causes of any other event and find evidence of why it occured.