I was considering buying an Infiniti Q50S Hybrid but it is $4600 Cdn more than a non hybrid. I drive 36000km per year so the battery warranty is only good for about 5 years after that I'm on my own and once the batteries start to go the replacement cost is $11,000 Cdn.

I'm wondering how someone could consider an extra $15,600 for a car that only lasts for about 5 years before some major bills may be incurred.

Some say to just sell the car before the warranty expires however anyone with half a brain that is considering purchasing the car would have to consider the $11,000 Cdn battery replacement cost when determining the purchase value of the used vehicle.

So I'll ask again why would someone by a Hybrid?

Financially, buying a hybrid never makes sense. If you're looking for the fuel savings to pay for the extra costs of purchase and battery replacement, it's not going to happen with only a 35% reduction in fuel costs.

People buy Hybrids for two reasons: One, to be able to pound their chests and tell everybody how green and virtuous they are, and two, to actually try and make a difference by reducing their carbon footprint.

The Q50 hybrid certainly fits the bill for reason 1, but not for reason 2 -- there are plenty of cars out there that will beat the fuel costs of 31 MPG combined. There are only a couple of cars out there that will fit the bill for reason 2, but, of course, they do not have 3.5 litre v6 engines that can go 0 to 60 in 6 seconds.

Bottom line is, if you want a Q50, then get one -- but not the hybrid, unless reason 1 is worth $16,000 to you.

Just one man's opinion.

The other thing to look at is the Q50S Hybrid is the fastest Infiniti out there at the moment (production-wise). It's faster than a gasser S model by a good bit off the line (if that matters to you, but the performance-oriented buyers for this car are opting for the hybrid model quite a bit, surprisingly enough).

I just picked up a Q50S myself (gas model, non-tech) and I have to say it's quite enjoyable by itself. I would rather not have to worry about all of the other crap that goes with maintaining a hybrid, especially if the cost for that is so much more.

I tend to agree. It would be great as a lease or if you trade-in every 3-4 years (which usually does not make financial sense)

When considering a hybrid there are many factors to consider. For me, the main factor is what kind of hybrid to consider. Infiniti hybrids are a different breed than what we usually think when we hear 'hybrid'. Although they achieve higher mpg than a normal gas engine, they aren't the miserly formula that you find in a Prius, for example. Infinit is on the performance end of the hybrid equation, providing more power and torque than the standard gas engine with a slight increase in mpg. As stated above, the Q50s hybrid is the fastest Infiniti while at the same time, achieving higher mpg than a normal Q50.
We have to consider what we value most. Is it just about getting the most miles from a gallon of fuel or is it about performance and power with the added benefit of a smaller increase in mpg?
As for actually 'buying' a hybrid, I wouldn't outright buy one for the following reasons. Hybrids have been around for years, but they are still a work in progress and every 2-3 years there will be major changes in their mpg and performance. That said, how could get a decent price for your 4yr old hybrid when the current model has a vast improvement yours doesn't have?
The Tesla (a complete battery car) is the cutting edge and even those buyers are now faced with a dilemma. In the next year or so, the Tesla will have rapid charging that reduces the charging time to a fraction of yours, will have even more power, and upgraded systems. If you bought one in the last 2-3 years, yours is now obsolete even though you paid nearly $90k dollars for it!
The same will happen to the gas hybrids and I don't want to be in the position of trying to sell my 5yr old hybrid that is less efficient, less powerful, and closer to the dreaded battery replacement.
That leaves leasing. If you lease, you have no ownership and no equity. But you also have no worries at trade-in. The sour end is that you have to either buy it at the agreed price or switch to a new lease on a new model with another down payment and no cash left over as you would have by selling the old car. However, in the case of hybrids, you also have no ill effect of having a hybrid that is clearly less advanced than the current model and trying to get a decent price for it. The dealer eats that when you turn it in ... and I'm sure that was partially included in the payments required during your lease). That said, leasing will let you keep getting the latest advances on the newest models as long as you are OK with never ending car payments. Lots of peeps buy regular cars, make the final payment, and then immediately start looking at a new car, which ends up the same - never ending car payments. So for them, leasing is a great deal - lease payments are lower than loan payments, and a new car every 3-4 years. If you are one of those people, than leasing shouldn't bother you at all.
If, however, you are the person who buys a car, makes the final payment, then keeps the car for many years afterwards, you won't be happy losing all those years with no monthly payment.

^^^ this person has it right