|A couple of local car hire companies: Enterprise (Hammersmith), ZOOcars (Hardwicke Road). Also, a CW4-er mentioned that Robin & Day, Peugeot dealer by Chiswick Roundabout, hire cars at a reasonable rate. We've used Enterprise several times over the years and they've been fine. They do ask for £200 deposit (on credit card) but it is repaid immediately on return of the vehicle.|
Otherwise try one of the consolidators like www.auto-europe.co.uk. Some of the best offers are at Heathrow if your sister is prepared to pick up from there. One bit of advice using consolidators is to look carefully at the offers. Though tempting to go for the cheapest, sometimes the slightly more expensive includes excess waivers, etc.