Why yawning is contagious? Skoda Superb.

I had this doubt since very long time. But it wasn't as important as "what's the meaning of life?" Anyway, I suddenly remembered Internet and it's frontend, Google to clam my restless mind.
I realise, just linking up individuals and their petty information databases will not lead to answers for all questions. Oxygen deprivation, evolutionary habit,...enough silly theories which cannot be proved either way.
For instance, the theory that, oxyge deprivation makes everybody in the room yawn at almost same time. How does that explain yawning when you watch somebody yawning on TV?
Ok, this entry will induce yawning if this isn't stopped here.
My 5 yr old son other day wanted to buy a 2.7 million rs Skoda Superb. ( A car priced at par with C class Benz but with features of S class) Ok, I never went enough near a C|S class Benz to know the difference.
The features of Skoda Superb included Rain sensors (must be useful when you are using mobile while watching movie on dashboard DVD player while driving while..) ,rear parking assiting sensors, a small refrigerator, double AC vents and 100 little things which any owner may use for 1 time max.
Anyway, let me cut the chase. I had no money to spare for or I was cruel to crush desires of my adorable son. Sales pitch of dealer's representative. (repeated 4 times) "You live only once, Sir". Yeah, I know, you need not remind me and depress me. And I don't want to be a joker & pauper moving in such an expensive car.