Can I file state taxes on a vehicle I am buying with a co-signer?

[katherinefb]

I live in Washington state.

[xmasbaby0]

Whose car is it---and who is paying for the car?

[Opus 17]

Car taxes are assessed against the person whose name is on the title, regardless of whose name is on the loan or who pays the payment.  Only the person who is assessed a tax, can deduct the tax.  You can't take any deduction paying someone else's tax assessment. 

Then, if you are on the title, you must also be the person who actually paid the taxes or registration fee.  

[katherinefb]

My boyfriend co-signed on the loan for me. It is both of our car. (But it's really mine shh!)