Whatever year I go back to, it will be the same for all models. This research covers all cars, not just the Corolla.Most model years from 1999 on are now included in the survey, and other years are close. But more participants are needed in all cases.
For the full set of results, and sign up to help (if you haven't already):
TrueDelta Vehicle Reliability Survey results
I signed up for this site after finding out about it on a PT Cruiser forum. Since I'm leaning towards selling my PT Cruiser to get a Corolla, I've been reading up on things here. The site, as has been stated, is genuine. The operator doesn't spam you. He simply mails you a periodic message to say, "Hey, it's a new month, please enter any repairs for the last month at xyz link." Simple as that. Very non-intrusive.
But like another member stated above, I do find the site to be confusing...and it took me a while to figure out why that is. It needs to be displayed in a Reader's Digest version. The site could be broken into a more 'explanatory' section in one place and the nitty-gritty sections in their own. One thing that really throws me is that there are different parts of the site (Reliability, Fuel Economy, Repair History). Maybe they should be referred to as Measures, Categories or something along that line, with a noticeable visual change between each. Making the Fuel Economy pages mostly green, the reliability yellow and the repairs a red theme would differentiate them, since each survey is not integrated.
Another thing that really gets me is the constant use of the term Panel. I never quite know what context the term is used in. From my end-user perspective, the Panel could be the Reliability survey, it could be the results of all cars when there is sufficient quantity of each to start making calculations or it could simply be a database of cars.
The site is useful and doing it's job, but I find I don't spend much time on it because of the usability. The last thing that I don't like is that the server times out if I leave and come back another day. It doesn't seem to support a "Remember Me" kind of feature.