Q: My 2007 Chrysler Town & Country minivan has 75,000 miles. The driver's side passenger door has rusted through at the bottom. Three body shop estimates for the rusty door replacement come in about $1,800. Otherwise, the mechanicals seem fine. Is it time to buy a new van, focus on replacing the rusty sliding passenger door or ignore and drive the vehicle into the ground?

A: This is a common conundrum for owners of "mid-life" vehicles. Not knowing the exact model you have, I'll use the T&C LX 3.3-liter V-6 for the example. Checking Kelley and NADA Blue Book values, trade-in is $3,700 to $5,700 depending on condition. Noting the rusted door and the near $2,000 repair cost, let's work with $3,700 trade-in value.

Your options are: 1) DIY door repair with bondo, duct tape, expanding foam insulation and spray paint, or a used door from salvage yard — perhaps $100 to $200. 2) Spend $1,800 to properly repair/replace sliding door. 3) Accept roughly $3,700 trade-in value on replacement vehicle. Even this might be somewhat high due to the "rust-through" on the sliding door.

Options 1 and 2 assume you will continue to drive the vehicle until it is fully depreciated, rusted out, used up and ready for the salvage yard. In this case, the $2,000 "proper" repair is basically for cosmetics only and does not add value, life expectancy or reliability to the vehicle. The DIY repair may not look particularly attractive, but it would suffice in this case.

Option 3 effectively includes the cost of "proper" repair as reduced trade-in value for your vehicle "as is." Trade-in value in "average/good" condition is in the $4,500 to $5,000 range. The difference in trade-in value, roughly $1,000, reflects the fact that the dealer can repair the door for significantly less than you can.

Which may be a key to your decision. By trading your rusted van on a new van, you effectively save about half the cost of "proper" repair. Plus you save the sales tax on the value of your trade-in. You also eliminate additional mechanical/body issues in the later years of your vehicle's life and you get all the benefits of driving a new vehicle. At the cost of the new van, of course.

In my earlier years, I always chose option 1 — the lowest-cost DIY option. Today, I'd be more likely to chose option 3 — the easiest and most hassle-free choice.

Q: I have a 2005 Chevy Malibu. While driving I have lost power steering and forward motion but the engine keeps running. I turned it off and on, and it drove fine for a couple weeks. Now it has happened again. Do you have any idea what this could be?

A: I'm somewhat surprised you haven't taken the vehicle into a shop or the dealership yet — the loss of power steering is a potential danger. My ALLDATA automotive database identified GM special bulletin 10183A dated May 2012 outlining "Special Coverage Adjustment Power Steering Assist" for 10 years/150,000 miles. This bulletin is an extension of GM's original bulletin covering loss of power assist due to "electrical input signal within the steering column." Check with your dealer to see if your vehicle is covered by this extended warranty.

I don't understand and can't explain the "loss of forward motion," as this would not be related to the power steering issue.