Complex sentence: First series cars were available only in Special trim and were called Polski Fiat 131p Mirafiori, cars of second series were known under the name Fiat 131p Mirafiori and were offered in L and CL trim levels.
Split into simpler sentences: First series cars were available only in Special trim and were called Polski Fiat 131p Mirafiori. Cars of second series were known under the name Fiat 131p Mirafiori and were offered in L and CL trim levels.