I did that (had about $80000 on hand at that point), the best it will offer me is the 2017 BMW I8, but in the code there are some very cool epilogue (or cut) cars that you should be able to get.
In particular the text seems to imply Julian can offer you his cool electric car in the end-game, but in actuality I only got the opportunity to trade the BMW for Z’s car, which unlike Julian’s own is inferior to the BMW at that point.
I mean I need more time to really code delve, it may be possible that those branches were trimmed and those cars were cut from the actual game as a result. 
I think it’s a 2008 S-Class and yeah that is a good, versatile car, although not terribly exciting with the recent advances in automotive technology if you play a high-tech character.
Code skimming my Julian playthrough I found references to these two cars my high tech loving mc would really like but I couldn’t find a way to obtain in-game.
Car and Code Spoilers
First up is the Hispano-Suiza, and the game suggests that if you are greedy enough, a good enough negotiator and have a high enough relationship with him Julian is prepared to give it up, according to this line:
“I’ll throw in the Hispano-Suiza, no problem,” Julian says. “Or the Camaro, whichever you want”
Problem there is my mc wanted the Hispano but the only car that is actually obtainable is the Camaro in spite of Julian’s statement and the game giving the opportunity to examine it and see its stats.
The second one appears to be epilogue only but it appears there is a section in the code where Julian can gift (a lover) the mc the 2020 Mercedes-Benz EQ, which admittedly makes more sense as a high-end, modern courier vehicle than the Hispano supercar:
" label key_toss
@{(julian_romance = “reciprocated”) He slides his fingers through yours. When he lets go, you’re holding|He tosses you} the keys to your
if car = “2020 Mercedes-Benz EQ”
new 2020 Mercedes-Benz EQ.* "
To me it looks like at one time a romanced Julian would have given this cool car to a lover mc (maybe one who doesn’t get greedy for the Hispano. 
) in the epilogue, but sadly it isn’t actually obtainable in-game, so unlike the Hispano this was probably cut-content.
Of course not being able to trade up to a more stylish and/or high-end wardrobe remains one of my main frustrations too. 