Where are you exporting from ? 3Dsimed directly to max ? Or do you pass through Cinema first ?
In any case, sometimes something can go wrong and scale is not correct. However when this happens, there is usually a "link" as compared to original geometry (relation imperial units to metric ones, or inch to centimeter, or mm to whatever) and that means there is an uniform scaling factor. What you can do then is uses this little trick:
Find an object for which you could approximate the size, and measure it. Depending on your findings, try to estimate the scale factor so that the object would be real size. Use that as scaling factor to the entire track to bring it to correct dimensions.
To test it out, you can then create a box the size of a car and see how that fits.
Hope this helps.. I've used this method more than once myself

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