Technical Lancia y10 seats in classic Panda

[Pandasaver 00]

Hello! I have read, that Lancia / Autobianchi y10 seats are a direct fit for the Panda (141a), so I got a full set of y10 seats, with rear seat included. The front seats were a direct fit, but, the rear seat despite being like 98 procent similar (same mounting points, same latches, same form etc:.), didn't want to fit. We have measured all dimensions of the seats and everything was identical except the lower seat plate was somehow 4 cm shorter. Is it still possible to fit this rear seat? What conversion is needed? As I mentioned despite the 4cm difference everything is identical to the stock panda rear seat. Did any of you attempt a conversion like that? If so, what are your experiences? (sorry for my english, I'm not a native speaker).

Panda seat:

Y10 seat:

 

[the green vanper]

Hello,

Would you be able to post photos of both seats, but the underneath? to show the differencies?