Thanks Don,
I appreciate your help but it looks like there is in fact a specific product code for the CRRuntime_32bit_13_0_16.msi installer and it appears to be {C5CFC037-B60E-4ECA-BCF0-2791A1153614}.
I am using this GUID to detect if CRRuntime_32bit_13_0_16.msi has already been installed or not and it seems to work.
Thanks.