Re: winter moisture problem
Any refurbished vehicle after an accident can show problems down the road that may have never arose if it was never involved in an accident. I'm sure you don't know; but depending on the severity of the rear end collision it may have loosened some components ever so slightly. It would be similar to driving over a curb, head on, at say 20-30mph! I'd make sure everything under the hood is secure and in place.
When you refuel, try 89 or 91 octane instead of 87. That may smooth out the power delivery. As the vehicle is two years old and with low mileage, change out the spark plugs for some new ones. Nothing too fancy is needed, just regular copper spark plugs every 30-40K will suffice.
'11 Ram Quad Cab 4x4 SXT 5.7L HEMI (stock); 48,500m
'06 Pontiac G6 GT 3.5L 220hp; 64,000m
'12 Chrysler 200 Limited 3.6L 283hp; 28,000m
'99 Taurus 3.0L 2V Vulcan 145hp; 154,300m - Traded
Amsoil in all vehicles!