Q: I have a 2008 Nissan Frontier with the 4-liter engine, automatic transmission and 88,000 miles. In checking the Internet, apparently 2005-2010 Frontiers, Pathfinders and Xterras have had an issue with the radiator/transmission cooler failing, which results in coolant getting into the transmission and ruining it. Nissan states that the problem will only occur with a small percentage of vehicles. Nissan has extended the warranty on the radiator to 100,000 miles albeit with a $2,500-$3,000 deductible. I am considering proactively replacing the radiator just for the peace of mind. Do you have any recommendations on whether I should replace the radiator proactively or take my chances?

A: I confirmed the information you provided and understand the dilemma you face. You have three choices. Recognizing that this problem apparently affects a relatively small number of vehicles, you could ignore the issue, continue to drive your truck and keep your fingers crossed. Or, you could check the coolant and transmission fluids for correct levels or contamination on virtually a daily basis, hoping to catch the problem before it damages the transmission.

Or, as you are considering, pre-empt the issue and replace the radiator now. Since a new radiator from Nissan lists for over $650 plus three hours of labor to install it, check with cooling system specialists for a quote on installing an aftermarket radiator. I found exact-fit aftermarket radiators for your vehicle priced in the $100-$250 range at local auto parts stores.

If it were my vehicle and I could have a new radiator installed for under $500 — or install it myself for about half that — I'd be seriously inclined to do so.

Q: I have a 2009 VW Jetta TDI. VW recommends oil changes at 10,000 miles using a synthetic that is only available at the dealer. My dealer says that VW hasn't seen any long-term detriment to using such a long interval. I understand the oils today are really superior in their protection. What do you think?

A: I really tried on this one. I researched, compared, pondered and cogitated — the whole nine yards. And yes, VW does recommend 10,000-mile oil change intervals on the TDI diesel engine. And yes, I don't think there would be any significant issues in following VW's recommendation.

But I just can't. I change oil and filter on our 2010 Passat Wagon equipped with the 2-liter turbo gasoline engine every 4,000-5,000 miles. I would do the same if it were the TDI. In this case, I see no downside in being pro-active on oil changes. Besides, it's your vehicle. You're responsible for it and you're going to pay for any repairs or excess depreciation. On top of that, the added cost for the extra oil changes is such a very, very small percentage of the total cost of ownership, depreciation, maintenance, repairs, licensing and insurance over the life of the vehicle, I don't think it should be a factor in your decision.

Q: I am 5 feet 3 and I really like my new 2014 Honda Civic LX five-speed manual but my left knee is only one tiny speck away from the dash and I am not 10 inches from the steering wheel, which would be dangerous if the air bag deployed. I called my dealership, my regular mechanic and a well-known body shop but I cannot find anyone who will install pedal extenders for me — apparently it's a liability issue. Could a non-mechanic like me buy pedal extenders and put them on myself?

A: Yes, you could. Pedal extenders are not difficult to install and I'm sure you could successfully install a set in your Civic. But before you do, check with local handicap/mobility stores in your area, specifically a store that specializes in building or outfitting handicap-equipped vehicles.

Go online to the National Mobility Equipment Dealers Association — NMEDA — at www.nmeda.com for a list of authorized handicap equipment installers in your area.