I didn't read this whole thread, so ignore me if this was covered, but the juice starts as soon as you sign the note. With even decent credit and a modest downpayment, you're going to blow through that $200 in interest charges immediately.
Honestly, is the price the problem with the wind buffeting fix? Does it seem too cheap?
If so, I have some pre-fitted wind buffeting diffusers available for $100.
Hypersonic Black Car Door Edge Guard Trim Molding Crash Scratch Protector 4PCS https://www.amazon.com/dp/B01NCK6STT/ref=cm_sw_r_cp_api_glt_fabc_RA1MFYT25RCKNHFAYWHP?_encoding=UTF8&psc=1
Unfortunately, this isn't true. It's not that there is a shortage of 3.5 or 4-inch tubing (and no one is claiming that), it's that most of these are bent and welded in small batches, many shops/manufacturers by hand. There aren't that many Supras out there. Definitely not enough to design...
All metal. Heat any piece of metal to 500+ degrees, and let it cool. It will do this. It doesn't have to be car-related. Even pans out of the oven do this.
Is there any reason why you wouldn't want your mods and the labor covered by insurance? I make sure to inform the insurance company for all mods in case of a total loss or theft. When you've got nearly 10 grand into a car, in addition to the 50 some thousand in cash you dropped, don't you want...