I don't know about Mazda, but some manufacturers still stock parts for older vehicles - it might be worth asking at the parts desk at your nearest dealer.

It's not the sort of part I'd expect a normal motor factor to stock, although they might still be able to get hold of one. Your best bet is probably to try one of the bigger parts chains such as eurocarparts (who, despite the name, also sell bits of japanese cars), unipart or camberley auto factors (the latter is local to the Berkshire/Hampshire/Surrey area, but I think they do mail order)

Mazda Air Mass Meter - where can I buy one?
Let $X$ be a polynomial  vector field  of degree $2$ on $\mathbb{R}^{2}$. Does there exist a nonvanishing  smooth function $g$ such that $Div(gX)$ is  a  proper map?Or at least the  zero locus of $Div(gX)=0$ is  a  compact set? Can we find this  $g$ an algebraic map or  at least in the  form $e^{P(x,y)}$ where $P$ is  a  polynomial?

Is there  a  uniform upper  bound $PDH(n)$ for the  number of  limit cycles of  a  those polynomial  vector  field of degree $n$ for which the  divergence is  proper or at least $Div=0$ is  a  compact  curve. For $n=3$, two what extent thses vector field  are classified in term of their coefficients
