Not at all - a car is not a target for a casual opportunistic thief - nor it is easily carried away and or put in a get away vehicle
Car theft and bike theft both require premeditation, except for those clowns that just leave their bike unsecured. The law however deals with car theft in a much more serious manner than they do bike theft.
I used to live down the street from 2 chop shops, it's very easy to get rid of a stolen car if the theft is for money. It is even easier to take it for a joy ride and dump it in the bush when you get bored.
I've had a lot of bikes stolen, being that I ride pretty much everywhere and (did) live on a town full of ice addicts. The large majority of those thefts have been from locations and times you wouldn't expect it a thief to hit. Like the entry to Coles at 4pm on a Sunday or a few metres from the entry to the cafe I work in during the day. Or an attempted theft from outside the pizza shop I was playing Buck Hunter in! He was in clear sight! But I was very focussed on not hitting the cows until a young gasser I knew came running in to tell me. The would be thief ran off without his loot as I came out of the shop.