@rickylil7 you didnt change the handling.meta file for your "handler" ;) and you also need to change the vehicles.meta for "handler" then, so you have to change the wheel scape, the wheel suspension, the wheel, and if its 4x4, or front, back wheel drive.

@carter84 when you do some more replaces, you would know after a time, it is always the same. if you use openiv, there is on top right always a searchbar, where you for example can type "gresley.ytf" if you want to change the gresley, then it searches and show all locations where to find gresley.yft. then check, which one is the newest, in this kind patchday3ng, and not x64e .... ... same on it, most time on the patchdays, there is also under levels, gta5 etc. etc. then a vehicles meta, and before a handling meta. that contains the "gresley" or the car you futured of.

if you change a car that only consists in a x64e folder, then update,update,common,data .... is your vehicles and handling meta for them...

Mean always, when you do a addon as a replace, or just rename a replace in other replace, alos fix handling and

vehicles meta, to get coorrect dials, hands on steering wheel, correct point of view (POV), correct sitting with your charackters, changing car sound, etc... other important stuff. (as example, - <dashboardType> is always for the correct dials working) .... and - <layout>LAYOUT_....</layout> always for correct the hands on steering wheel...

as example some layouts: LAYOUT_LOW, LAYOUT_LOW_RESTRICTED, LAYOUT_LOW_BFINJECTION, LAYOUT_LOW_CHEETAH, LAYOUT_LOW_DUNE, LAYOUT_LOW_ENTITYXF, LAYOUT_VAN, LAYOUT_STANDARD, etc...

also important often at end of vehicles meta, is ofthen the interieur. here example:
<txdRelationships>
<Item>
<parent>vehicles_btype_interior</parent>
<child>bc</child>
</Item>
</txdRelationships>

will change the interieur to a correct one ;) or better one that can fit. if you dont change on replace, you have wront interieur than the modder have. Mean, can look white, chromes, or just black, mean no colours or just same colour.

the files, carvariations.meta (not that important, just set up the npc cars how they spawn with colors, tuning, etc..) as carvariation says. dlctext you dont need from the addons to copy, just addon needed, not in replace neded.
vehiclelayouts.meta is also important, for tuning set correct and some animations including ofr example roof etc.
carcols.meta for correct lights (but since 1-2 years not needed any more, if you use some graphic mod, just use it, if coronas / lights effect shining wrong on your car)

important, handling.meta set for example correct wheel size, wheel scape, suspension, also that car not overroll, that car brake good enough and handling in driving is optimal ...

@yeetus211 with only change file names of replace, its not done. you will have all other stuff wrong then, the car is in, but all wront, no dials, no hands on steering wheel, no mirrors showing, car can overflipping, no suspension, wrong mass on car, maybe drifting too much to bad handling, etc... mean on each replace, you also have to set the correct vehicles.meta and handling.meta .. (only things on handling meta you dont need to change: gears, speed, driveforce, brake) .. but suspension, mass, pov (point of camera in car), layouts, dashboardtype, etc.. need to be changed always (cause each replace car have other dashboard or other layouts) ... so just change it to the one the modder always says, cause his car contains of this ones.

4/5 stars, because you dont explain the people the sections where they have to change the vehicles and handling meta ;) and your add-on is also not optimized that well in settings, but model is great