After driving Hyundai Elantra for 6 years, I'll do a simple comparison interms of the interior or what I have noticed.
Auto headlight off
Elantra - Yes
Lancer - Yes
Dimmer center light when closing the door
Elantra - Yes
Lancer - Yes
Electrical still working for few minutes after the engine is turn off (to wind up the window, etc)
Elantra - Yes
Lancer - Not tested
Red safety light at the door, provide visibility when doors are open
Elantra - Yes
Lancer - No
Backlit for all the power windows - front/back, driver side 4 power windows nicely lighted
Elantra - Yes
Lancer - No
Compartments (sunglasses, coin box, card holder, etc)
Elantra - Yes
Lancer - No
Additional 2 cups holder at the back (4 at the back)
Elantra - Yes
Lancer - No
Safety triangle at the boot
Elantra - Yes
Lancer - No
Good soundproving/ NVH (rainy days, motorcycles, etc)
Elantra - Yes
Lancer - No
Engine noice front the inside
Elantra - low
Lancer - high
Airbag/ABS/EBD
Elantra - Yes
Lancer - Yes
Look
Elantra - No
Lancer - Yes
Performance
Elantra - No
Lancer - Yes
