I owned one for 5 years, servicing every 3 months.
In that time:
1. Need to replace cat converter ($1,200).
2. Need to replace IMA ($2,700).
3. Need to replace transmission ($2,200).
4. Need to replace flywheel.
5. Wheels randomly seize up almost causing an accident.
Dealer doesn't know why ($100 diagnostic).
6. Need to replace engine ($3,800).
7. Need to replace transmission ($2,200).
8. Need to replace IMA again ($2,800).
9. Need to replace wiring ($550).
Used/aftermarket parts are hard or impossible to find.
2 of 3 dealers had extremely poor workmanship (I was a mechanic).
Car never lasted more than 3 months w/o something breaking, and every part on it is EXPENSIVE.
When everything was working properly, it averaged 60mpg in 50/50 city/highway driving.
Even with the IMA out, it still averaged 40mpg.
Honda dealers that hire qualified mechanics, not screwups.
Seats don't go down, extremely uncomfortable on road trips.
I purchased the CVT and have not regretted the purchase at all. I get an average of 52 mpg in LA with stop/go/AC. The car had 80,000 existing miles but Honda's extended warranty (150K) for the battery as well as the Honda Care extended warranty (7yr/100K) has taken care of any concerns. I enjoy the car so much that I will be selling my other car because I no longer drive it. Looking forward to the release of the 2009 Insight.
I drive mainly on interstate highway. My commute to work is about 96 miles round trip, all but 10miles are super highway. The vehicle has nearly 115,000 miles with an overall average mpg of 64.3. I haven't had any problems with the car and have replaced 4 tires once, and the front brakes just once. Because of the conditions of our Mass highways, I have had to replace the windshield twice and will need to replace it a third time before the next inspection. My Insight is a 5 speed manual with air conditioning.
Gas mileage and the ease of driving. The instrument panel provides very useable instantaneous and long term information about the fuel mileage. I continue to use the instantaneous numerical and bar graph to tune my driving to get the best mpg. I think all auto manufacturer should provide these gauges.
There are serious blind spots on both the driver and passenger sides of the vehicle. Because of these blind spots it is very important that the outside rear view mirrors be clear. I believe it would be extremely helpful if these mirrors are heated.