5SGTE
I kinda like your idea but I think I'd add a top plate with a semicircle in it, kinda like this _/\_ to locate the hose.
Mine seems to be supported well but I can't help but think there is some added stress on the hardline.
My earlier revisions had the plastic wrapping around the hose so it was a snug fit. I will find the photos.
New wheels and tyres purchased. Tyres are Toyo R888R 195/55/15 and 225/50/15, ordered from Demon Tweeks UK, arrived within 10 days. Got them mounted on stock 15" rims today.
4 stock 15" rims fit perfectly into the boot.
Whipped up a quick aluminium strip to assist holding up the under body plastic. 2 of the 3 bolt sections had broken away. Works a treat. Thanks Doug for the tip at the tech day :D!