I have a 2012 Q7 TDI which I bought used. I am getting ready to do the 35K mile service soon. I see that the fuel filter needs to be changed at 35K.
Are there 2 filters? When I open the hood, I see this one right away that looks like an inline filter:





That represents part numbers 8K0127400A ; 8K0127400; 8K0127400C; 8T0127401A (different numbers, all the same part).

But when I was researching fuel filters there seems like there is a version that is vertical rather than horizontal with a drop-in/pull-out filter unit within a housing, similar to an oil filter.
When I follow the lines out of the fuel filter pictured above, they seem to lead to an area under the silver Audi cover and likely to that second filter unit. The part numbers for that part based on my research are any of the following (all the same actual part): 7L6127434C ; 7L6-127-434-B; 7L6127177B; 7L6127434B


So, do they both need to be changed?

Thanks,
Albert