Being an Aerodynamicist and a Race Engineer requires very different skill sets and route. So, I'd advise trying to decide what path you want to follow first. Look into their career roles, read up on technical aritcles and watch some videos etc. do some courses, that's what I did to decide what role I wanted in motorsports. If you decide to go for Aero, Southampton is indeed the place to be at. Delft is equally at par course wise but you would be able to get more hands on experience opportunities studying in the UK. If you want to be a Race Engineer, you would need to know Vehicle Dynamics very well. Oxford Brookes and Loughborough are definitely the best choices for that. Go with Brookes if you are sure about motorsports and eant to study everything motorsports focused, they have the best FS team, course modules and industry connections. Loughborough won't be motorsports focused but would make you more well rounded to work in the automotive industry since they teach stuff as Battery Technology, Automated Vehicles etc. I am personally not interested in such topics and want to dive into motorsports from day 1 and the atmosphere at Brookes really supports such ambitions, so I decided to go for Motorsport at Brookes and will be starting in September
Feel free to get in touch further, I've researched this whole topic quite a bit haha