I have only owned Toyota vehicles, a Celica, 4 Runner and now the Highlander. All in all I like the Highlander, however I do have one big gripe, for some reason, when the car is on, but not moving or moving slowly, the car vibrates (which can lightly be felt in the steering wheel, foot pedal, and seat). I took it to services at the Toyota dealership and was told that it was the motor idling and the sales manager even told me that this was a glinch in the 2006 four cylinder Highlander model. I don't know.
I bought this SUV late June after considering multiple sedans and other model SUVs. I test drove the Highlander and instantly fell in love with the drive and comfort. So far, gas mileage is OK (haven't really officially clocked city and highway) and the air conditioning system is great! (Cools the car within seconds.) Overall, this car is a great value for the money. The 4 cylinder engine has enough pep for both highway and city driving so I didn't see a need to purchase the V6 model.
Rides like a mid sized sedan. No blind-spots! Easy to get in and out. Outstanding tow vehicle for small camping trailer (Casita about 3000lbs). Finish holds up just great. Minimal maintenance so far. Put heavy duty struts on at 110000 miles. Heavy duty premium brakes and rotors at same mileage with serpentine belt and timing belt at same time. Flushed transmission and trans-axle at same mileage. Always used full synthetic oil. Wash monthly and as needed. Wax every 6 months. Vacuum weekly.
Note we replaced the 2006 Highlander with a 2016 Highlander Limited Platinum in January 2016. Love it! Higher towing weight was primary reason for the change. GF
Our Highlander has been nothing but flawless. Not a single warranty issue and it does an excellent job as our family vehicle. The only thing I would have done different was not get the 3rd row seat. It was never used once in the almost 4 years I have owned it. Also, if you want to buy a first generation Highlander, I highly recommend getting a 2005-2007 model. This was after the Minor Model change and the interior is much better than the 2004 and earlier models.