Liners? I'm confused!

[GreatSoprendo]

DS1 is 11 weeks old, and a 98th centile giant who has already grown out of his carrycot. Fortunately we borrowed rather than bought the travel system! We have now just ordered a Britax Bsmart 3 pushchair to use instead as it can be parent facing and lie flat - being delivered this week.

What I don't get is do I need to buy a liner for it? Will DS just rattle about without one? Or get sweaty? Do I need some kind of head hugging thing too? Or do I need one of the lambskins I keep reading about? I'm thinking summer time here - I can see I will need a foot muff type thing for winter.

Thanks and apols for the idiot novice questions!

I had a 98th Centile DS and also have a Britax BSmart 3. We had DS in the Britax carrycot to start with but once in pushchair (around 3-4months) he's been fine with no liner, doesn't rattle around. We just used plenty of blankets in the winter. I do think though that a liner would of been useful if bought when he was younger, just to keep it a bit more clean!

Thanks so much for your replies. The 'keeping the pushchair clean' aspect is one I hadn't thought of at all! Will definitely get one now.

Thanks again.