Well, uh, sort of.
Three years ago I bought a used '97 Aerostar with 60K miles on it so my wife would have a daily driver that all of the kids and their stuff could fit into. At that point, I sold my fun little '92 Saturn SL sedan to some friends for $1500, and took over daily use of our larger '97 Lumina LS. Commuting over 100 miles a day, I like the added protection that extra space and greater mass provide. We'd bought that in a lease fleet turn-over in October of 1997 for $14,250 with just 25K miles on it, and it's been a decent car. The odomoter has recently topped 190K on the Lumina and the Aerostar is just over 160K. I've put $3000 into each of the two transmissions in the last 12 months, so both vehicles should be good for another 150K-200K miles.
I haven't bought a NEW car -- EVER -- and likely won't unless Congress makes auto loan interest tax-deductible, which they will do in the first Congressional session after Hell freezes over.
Hope you are getting full satisfaction out of your Highlander. Just be sure you keep it long enough, and drive it far enough, that your savings on overall fuel expenses more than offset the added expense of the hybrid setup, otherwise it's no more than an unprofitable exercise in environmental altruism. I want you to feel good about your car for more "green" reasons than just frogs and birds and trees. Make sure the purchase puts some "green" back in your pocket over the course of its lifetime.