There are now 8 i30 owner reviews:http://www.carsurvey.org/manufacturer_Hyundai.htmlfor stastical purposes it would be good to have more!
Also remember performance and running costs cover many different models, from 1.6 petrol to 2.0 diesel with the i30, and other makes also could have many different models and engine sizes. Also cars made in different countries could have different reliability.
Interesting average reviews:Hyundai i30 Performance petrol and diesel together 8.4 (just diesels 8.7)
Reliability 9.3
Comfort 8.3
Dealer service 8.5
Running Cost (higher is better) petrol and diesel together 8.6 (just diesels 8.8)
Average 8.62Mercedes A-Class average reviewPerformance 6.8
Reliability 6
Comfort 6.2
Dealer service 5.7
Running Cost (higher is better) 6
Average 6.14Volswagen Golf1975-2008
Average Performance marks 7.3
Average Reliability marks 7.3
Average Comfort marks 7.5
Average Dealer Service marks 5.4
Average Running Costs (higher is cheaper) 6.7 \
Average 6.84Toyota Corolla1969-2008
Average Performance marks 7.3
Average Reliability marks 8.9
Average Comfort marks 7.3
Average Dealer Service marks 7.1
Average Running Costs (higher is cheaper) 8.2
Average 7.76Ford Focus1998-2008
Average Performance marks 7.3
Average Reliability marks 7.1
Average Comfort marks 7.5
Average Dealer Service marks 5.9
Average Running Costs (higher is cheaper) 7.0
Average 6.96Peugeot 307Average Performance marks 6.5
Average Reliability marks 5.7
Average Comfort marks 7.6
Average Dealer Service marks 5.1
Average Running Costs (higher is cheaper) 6.2
Average 6.22Hondaa CivicAverage Performance marks 7.5
Average Reliability marks 8.5
Average Comfort marks 7.2
Average Dealer Service marks 7.0
Average Running Costs (higher is cheaper) 7.8
Average 7.6