One of the places you can start is with a cover for your steering wheel. Most standard cars come with a cheap looking piece of plastic. Almost every car has a black steering wheel, regardless of how the rest of the interior is dressed out.
In addition to dressing up your car, a cover will also hide any wear or damage that may have occurred to your steering wheel.
Some points to keep in mind.
First you will have to install the better ones, and it takes about an hour. The real cheap ones have elastic and you can just slip them on in a minute or so. You will not enjoy having one of these, so I can't recommend them at all.
Second, insist on leather. It gives you a better look. It is also warmer in winter when the temperature drops. You don't want to freeze your hands to the steering wheel. Leather also gives you a better grip, and this is important from a safety standpoint.
Third, make sure that the product was designed and sized specifically for your car. You should be able to order one based on the make, year and model of your car. One size does not fit all.
Fourth, check to see if your car has a cover on the wheel already. If it does, you can either remove it, or you may have to order one size larger to get a better fit.
And finally, you do not have to stick with one color. Some companies offer a "Euro" style cover which has one color for the top and bottom, and another color for the sides. Very unusual looking and it really stands out, and separates you from the pack.
 
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