hi sir,
ideally (and based on banks), the monthly amortization should be around 30% (at most 40%) of your monthly amort. in order for you to still have headroom for future and unseen expenses.
I guess your annual salary is around 400k and would give you a monthly salary of around 30-34thou (not being slashed with witholding tax of at least 7thou)...
Given that into perspective, I think the question on affordability depends on the amount of d/p that you're going to pay: a civic 1.8v (a/t) * 20% d/p will have you pay at minimum 16.5thou per month for 5 years while a jazz 1.3 a/t * 20% d/p will have you pay around 14.5thou per month. In an IDEAL scenario, both cases are NOT advisable. if this would be put into consideration, IMHO, you need to shell out at least 35% - 40% d/p so that you can IDEALLY afford one.
This is only me since I am more of a traditional payer

Hope it helps.