Lightweight car seat for 3.5yr old to use in hire car abroad?

[bettythebuilder]

We're going to Portugal in a couple of weeks, and will be hiring a car.
Can anyone recommend a lightweight car seat to take with us to use in the hire car?
Last year the car hire co. tried to fob us of with a piece of foam (I kid you not) so dd and I had to wait in a hot dusty airport car park for an hour while dh sorted it out- something I thought I could avoid by taking a lightweight seat with us.
Any advice?

Anyone.....?

depending on her height and weight she might be able to use something like the graco booster with back.
as a rough guideline they are for over 4yrs old (I think), but by the time our DS was 3yr he was well over both the height and weight requirements for this chair.

or just take your regular car seat? most airlines seem to take them free of charge in the hold. we have done this several times with our britax freeway.

Thanks gloworm. She's not particularly big, but I think something like a well padded booster would be ok.
The problem with our car seat is that it is really heavy and very unwieldy (is that a word?) so I thought a nice lightweight one that I could put in a little suitcase on wheels and check in would be good. Plus, we're going with a low cost op, so they may charge us for excess hold baggage.
I'll check out the graco booster, ta.