Mate, have a scan over here, this is my recent experience...
I've mixed opinions now I've come out of the other end if I'm honest. On one hand, I did fuck all wrong, was inconvenienced by some daft bint who couldn't drive, so why shouldn't I have a decent car for a week. On the other hand, the way the Solicitors, Claims Management Company, kick-back for whoever referred the lead (local garage/insurance company) and hire car company all cream cash from the insurance claim, which in turn hikes-up our premiums, makes my piss boil.
It's exactly as Matt has described before. My case took about a year to complete. I was asked to provide statements to say why I needed a replacement car, why I didn't simply get a cheaper hire car for a fraction of the price then claim it back myself, why couldn't I have funded it myself (why did I use an expensive 'credit' hire company). I was asked to provide personal bank & credit card statements for 4 months from the accident to prove I couldn't have afforded it myself (they wanted business accounts too but I told them to swivvle on this). Loads of forms & statements needed checking & signing. I had a court summons however the claim was settled a week prior so no need to appear (thought I'd already kept the day free). A right fucking farce.
That said, I got my car sorted out pretty quickly & got a brand new TT for a week (not exactly like-for-like but at least it wasn't a Note). It was the following 48 weeks that was a pain in the arse.
The bill for my car was paid quickly by the other side (£2.5k) it was simply the bill for the TT they objected to (also £2.5k - for 5 days - though they claimed for 8 as I dropped it off on a Friday but the company didn't collect it from the garage until Monday - I made sure it was clear on the documents that I only had the car 5 days).
They settled out of court for nearer £1.5k. So, the other side saved £1k off the bill, but God know what the actual cost was once all the defence bills arrived.
Make sure you've got the insurance to cover your ass just in case the other side win (pretty sure it's usually bundled-in). And yes the paperwork arrives with the hire car and the chap watches over you waiting for his train as you speed read (if that) the paperwork and sign your life away. I had no idea what I was signing - niaively just went along with things.
Turned out OK in the end but was quite stressful (first insurance claim) and took an age to settle. On reflection I'd probably be happy with a 1.6i Astra for a week and concentrate on other things got 48 weeks.