i think the miata has a seat lifter also(little knobs on the side that lift/lower either the front or the back or both) so it might be slightly adjustable, i feel your pain most cars wernt made for us taller ppl(im 6'3 riding most bikes and getting in the 7 is a bitch, fits like a glove once im in tho , getting out is another story...) taking off the seat rails might solve your problem but you will loose the adjuastablity and mounting is key(you dont want the seat coming loose in a collision) ive sat in a miata before and it wasnt to horrible uncomfortable but i couldnt see myself driving the car on a daily basis. my advice is to sit in one, dont have to test drtive just go to a dealer or check out the classifieds and ask to sit in one, you will find out if you could handle it. its also mostly based on personal preference, some ppl like more room than others, i had to slouch more than id have liked too but thats me.
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