2003 Accord coupe EX, hideous shake

Hello, I have a 2003 Honda Accord coupe, EX, with almost 88,000 miles on it, and ever since ive had it ive notice one thing wrong that it does, and believe it or not it only choose is to do it at 4 locations and those 4 locations only, it doesnt matter if its warmed up or not, but what it does is when im crusing down the road doing 30 or 40 the steering wheel starts to shake, along with the gas pedal I think, I can only imagine what it looks like from the outside, or what its doing under the hood, but it does it over the bridge in my town, up a hill on the way out of town, down the main road, and the road i leave my house from which the last two are both flat surfaces, I took it on a road trip to Colorado, Las Vegas, California, and it didn't do it once, over the course of 4000 miles, and the front two tires match, the back two are different and once is almost out of tread, however im getting 4 new tires very soon, so they all match, but it is beyond me what this problem could be, and you can't stop it, well I suppose you could by slamming on the brakes, but speeding up only makes it worse, and its only at those low speeds, you get passed 50 it rides like a dream, i bought this car from the dealer with 65,500 miles on it, and have had it for 3 years, and just recentley totalled my daily driver, so now am forced to drive this car, and this problem is really irritating, so ive put just under 23,000 miles in 3 years, normal driving , nothing extreme, any help would be much appreciated, thank you :]

Forgot to mention this because I know the horrors of Accords with the V6, and thankfully I have the newley redesigned 4 cylinder for 2003, I didn't even know about all the V6 problems, and I sure am glad I didn't get one with a V6.