I just wanted to mention that few of these mods improve top speed to any significant extent - but you may find they improve acceleration and contribute to a smoother running engine.
32mph for one of these "80s" really isn't bad at all - you've done well! Unfortunately evil math saz that with a doubling of speed the drag quadruples, so wind resistance is your enemy here - anything past 30mph is hard fought for
I know right? Maths... I hates them o_O
Having said all that and even knowing the vast majority say the boost bottles have little/no effect - I may still get one as I've run out of lil tinkering mods to do lol