 Michelle, the hum may be the 
idle air valve. When stuck open it
makes a loud hmmmm noise. The car is 
fun to drive, excellent handling on 
even pavement. Loses grip on 
potholed/uneven surface. I have never 
had a powertrain problem. It has great 
sounds, especially when I replaced the 
tires with quieter and equally grippy 
Kumho tires. I have however had 
many "feature" problems. My moonroof 
stuck in the popped position 3 times, 
the foglights burning out regularly, 
every 6 months. The TSB on the dash 
cover. The rear suspension squeeks on 
cold days. The stock radio was weak. 
The rear bumper fits poorly.