AEC Mk. II
The AEC is a relativly cheap tank destroyer on wheels. This is pretty much the only dedicated TD you will find that can move so fast. It's weapon is not particularly powerful, but can still hurt against even medium tanks. Another point to note is it's increadably fast projectile velocity, comparable to the soviet Zis-2 even.
The AEC range is below average, often getting it into dangerous situations. It's lack of armor and poor range will often spell instant, unexpected death.