Ah ~ I am guilty this year too ... I have recorded all my revenue coming in but my receipts are all sitting in their envelopes waiting to be recorded too at this point I am just going to wait until a cold icky day in January and get it all done than!
Mortage wise my understanding is that it is the shared use of home equation ... aka the square footage of your home / the square footage used for daycare X the number of days in a year / number of days you are open x 24 hours in a day / number of hours you are open = % you may write off on the MORTGAGE INTEREST AND PROPERTY TAX paid for 2012 only.
As for the car ~ depends on if you like doing math or are using a program that does it for you if it is worth it to you ... every $1 in legitimate expense you can find lowers your taxes paid by at least $0.20 cents
Here is the Daycare in your Home link ...
http://www.cra-arc.gc.ca/tx/bsnss/tp.../menu-eng.html