Admittedly, "entry-level" is a bit of a stretch, as one
We can hear some of you scoffing from over here. Never forget, the Atom weighs just 1,350 pounds. Meaning that a 219-horsepower engine can catapult the car to 60 mph in 2.9 seconds. For the sake of silly comparisons, the 638-hp supercharged Corvette ZR1 takes 3.3 seconds to achieve the same velocity. Also, don't forget we're talking about the entry-level Atom. A 245-hp version can be yours, as well as a supercharged 300-hp example. Of course, those will cost you extra.
However, if you're looking to spend a little less, TMI AutoTech can still accommodate you. For an undisclosed sum they'll happily sell you a rolling chassis and you're free to cram whatever motor you like into the Atom. Might we suggest the LS9? Though if cheap(ish) topless, doorless motoring really is your thing, a fully built Se7en can be had for around $30,000 depending upon the options. And unlike the "porky" Atom 3, proper Se7ens usually weigh in at 1,200 pounds. Just sayin'.