Both of these cars can be built in Machinas (and might actually do well in a race). Part of the fun of Machinas is creating your drivers and tricking out your cars. You will be limited in what you can build; You only have so many points to use to buy equipment for your cars and personality traits for your drivers. In addition, cars have maximum weight allowances. You can actually go over this maximum, but it will cost you speed. My ram car for example has a maximum weight allowance of 7 (weight is abstracted.) The Spiked Ram weighs 4. I'd also give my car the Heavy Armor Upgrade which weighs 4 as well. I've gone over my weight allowance, which you can do, but now my car will be slower since it is overbuilt.
This would be a sacrifice I'd be willing to make. The ram adds to my "Bashing" ability, and the armor upgrade takes away from both an opponent's Bashing (which makes my ram even stronger), and from his "Shooting" (to help protect me from my own Shooting weakness.)
With around 70 different choices for your car and driver, there should be plenty of options and combinations to keep you busy.
Or you could just put Quad .50s on your car and call it a day.