should I rustproof? timing?

Just picked up a new 2010 Tacoma 2 weeks ago and I live in Northern Michigan.

Should I get it rustproofed...now, or in the spring, or does it matter?

 

If could do it all over again, I would have certainly rustproofed my 06. I live in northern Vermont where they salt liberally 4-5 months of the year. My undercarriage, even with weekly diy pressure washes is very rusted. Granted some of it is surface rust but the welds look particularly affected which along with the recent frame rust issue of past models, does not give a warm & fuzzy
Go for it as soon as you can if its available & can afford it. I do not think you will start a thread in a few years saying you wish you hadn't.

Congrats on the new truck and welcome to TW

 

Would hope the first winter you'd be ok. I'd probably do it in the spring or summer when she's clean and most Ziebart or local bed liner shops do it cheaper, last summer saw ads as low as $199.

See my pics icon for what 4 winters did to mine. Since then have undercoated myself.