If you want daytime running lights, just turn on your headlights...!
Would certainly do the job, and as long as you follow the rules about when to use main or dipped beam, perfectly allowable.
Doesn't have the bling factor though ;-)
I read somewhere recently (can't find the reference now) headlights account for about 0.2l/100 km fuel consumption, so might save a small amount of fuel if using LED lights.
I'm a bit old to be overly concerned about 'bling factor' when choosing my vehicles..!
Just buy a new car - daytime running lights are a legal requirement in Europe now I think (and several US states) so most of them come factory fitted!