just wondering if i can fit springs ment for a polo onto my fabia? part number is..SU-SP-HR-29333-3

any help much appriciated?

yes they fit

Same chassis, so as long from the same engine'd polo 9n, you'll be OK with spring ratings etc.

so going from a polo 18t to a fabia 1.4mpi is a no go?

You'll need to research if its specifically 1.8 springs or not. Probably will fit fine, but on your car the lowering will be less as obviously a 1.8T engine weighs more than a 1.4 n/a.