I've done the .co.uk thing several times and never had any problems collecting the car. That being said, EVERY time, the agent was clueless how to pull up the reservation including, correct rates on the contract, coverage being included, applying coupons, etc. (I posted a thread a while back about getting different prices when you try and view your res online). I always get the pitch that "Coverage 'may or may not be applicable in the event of a loss, regardless of what the contract says.'" Every time I spend 10-15 minutes arguing with the rental agent, giving them the entire reservation (all ~5 pages of printouts), and waiting for them to figure out what to do. It works out, but it's a royal pain.