Infant car seat adapters for Peg Perego?

We were looking at a Peg Perego Martinelli stroller today. The clerk informed us that there is a bar you can buy for $20 that attaches to the frame so you can snap your car seat into the back seat. They didn't carry the Tender Twin, but she thought you can do the same thing with that stroller... does anybody know if you can do it with the Tender Twin as well?

I checked the Peg Perego website and didn't see any info on this feature.

Thanks!