A car hire firm has recorded the lowest customer satisfaction rating of any operator in seven years, according to a consumer group.
Budget firm InterRent received a score of just 31% in an annual survey by Which? Travel magazine.
Customers were subjected to filthy vehicles, lengthy queues, pushy sales staff and unexpected charges, according to the research.
With an average price of £21 a day, InterRent is one of the cheapest car rental companies around, but one customer reported: "I feel like I got what I paid for."
It operates in 33 countries, mainly in Europe.
Spanish company Goldcar - which charges almost twice as much - had languished at the bottom of the Which? Travel table for four consecutive years. It has shown few signs of improvement, with a customer score of 42%.
Out of the 14 companies rated, InterRent and Goldcar were the only ones to receive just two stars for customer service.
They are both part of Europcar, which has received complaints in relation to claims of overcharging customers for damage repairs. The Serious Fraud Office has said it is aware of the allegations.
Europcar was the worst performer of the major car hire brands in the survey.
Auto Reisen, which operates in the Canary Islands, scored the highest rating for the fifth year in a row, with a 96% customer score.
It received five stars out of five in almost every category, including value for money, as it charges an average of just £16 a day with no excess and no unexpected charges.
Enterprise was the highest rated worldwide firm with 78%.
Customers described the company as "friendly" and "flawless", with one stating that it "never tries to sell me any extras I don't need or want".
Which? Travel editor Rory Boland said: "While we certainly don't need another shoddy operator in an industry already plagued by unscrupulous practices, InterRent's poor rating shows why it is more important than ever to vet your car hire company.
"Providing customers with good value, clear pricing and hassle-free car rental should be standard, so we are happy to see firms like Auto Reisen and Enterprise showing their rivals how it's done."
The results were based on 2,145 experiences. Only companies with at least 30 respondents were included in the analysis.