The staff tried to charge us 100 PLN for “early pick up” when the amount around £13 was showing on our booking. He recalculated it to 73 PLN after I questioned it

Great platform, easy cancellation and rebooking.

AVOID AT ALL COST. Dishonest to downright fraudulent rental place. They found small scratches on the car after I have returned it, charged full deposit (which is $500, way more than this should be charged), and refused to release ANY documents that would let me file an insurance claim against my travel insurer. They operate this "preagreed upon penalty" which basically means that if there's ANY damage (like $10 worth of damage), they will charge you full deposit and don't have to give you any documents. Maybe it's legal in Poland, but it is not how international insurance companies and car rental companies operate. Renting from this place you risk getting overcharged for any damage (we're talking kind of damage that in US would just be ignored) and no way to claim your insurance on it. FWIW, I asked a friend, Polish lawyer, if I have any recourse - she said that I could sue them if I wanted, but altogether I should've asked first before renting, because they have the worst opinion locally.

I was very disappointed because I got a different car than it was guaranteed

I wanted an auto but was given a manual instead. After a slight delay, Panek managed to find another car - which was in a significantly higher class - and let me have that at no extra cost. Well done, Panek!

Finding my way back to the car rental parking at Warsaw Chopin airport was a terrible experience